This is a collection of 800 technical terms you may come across during keyboard building and customization (theory and practice of keyboard building, logical layout design, typing and ergonomics).
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0279 - A size/type of {Mill-Max socket}s with long tails and hexagonal lips before the main lip. On a {PCB} with good tolerances this can be pushed in without soldering, but this may expand the hole and damage the PCB.
0305 - A size/type of {Mill-Max socket}s with a thicker lip compared to {7305}s. The long tail may be a problem with tight spacing as they may touch the bottom of the board.
0402 - A tiny {SMD} package footprint, 1 mm x 0.5 mm. {1005} in the metric nomenclature.
0603 - A small {SMD} package footprint, 1.55 mm x 0.85 mm. {1608} in the metric nomenclature.
1005 - A tiny {SMD} package footprint, 1 mm x 0.5 mm. {0402} in the imperial nomenclature.
1608 - A small {SMD} package footprint, 1.55 mm x 0.85 mm. {0603} in the imperial nomenclature.
1u - One key unit. A unit of key width. A single-width key, e.g. an alphanumeric one. Also see: {all-1u}.
1.25u - A key width of 1.25 key unit. E.g. {modifier}s of the {bottom row} on a {standard keyboard}.
1.5u - A key width of 1.5 key unit. E.g. Tab on a standard keyboard.
1.75u - A key width of 1.75 key unit. E.g. Caps Lock on a standard keyboard.
1800 - A slightly cramped {fullsize} keyboard. A {form factor} similar to a {96%}, but with some breathing room around the arrows and {F-key}s.
1n4007 - A type of {diode} with a switching speed in the microsec range.
1n4148 - Probably the most popular {diode} for keyboard projects. Switching speed in the nanosec range.
2u - A key width of 2 {key unit}. E.g. Backspace on a {standard keyboard}.
2.25u - A key width of 2.25 key unit. E.g. left Shift or Enter on a standard {ANSI} keyboard.
2.75u - A key width of 2.75 key unit. E.g. right Shift on the standard keyboard.
204g0 @ Krytox 204g0
205g0 @ Krytox 205g0
30% - A minimalistic {form factor} with only the {alpha}s, give or take. E.g. the Gherkin.
3203 @ Tribosys 3203
3204 @ Tribosys 3204
3u-12u - Keys with that width, expressed in {key unit}. Usually spacebars.
4-pin style - The more common {leg} type on the {upper housing}.
40% - A {form factor}/{physical layout} with only the {alpha}s and some {modifier}s. (No {numpad}, number row, {F-row}, navigation and arrow cluster.)
60/40 - A reference to a solder material with 60% tin and 40% lead ({Sn60Pb40}).
60% - A {form factor}/{physical layout} without the {numpad}, {F-row}, navigation and arrow cluster.
6.25u - The width of the standard spacebar.
6KRO - 6-key {rollover}. This is the maximal number of simultaneously pressed keys registered according to the USB {HID} Standard's boot protocol. Many keyboards keep this limitation for the report protocol as well.
70% - A quite rare {TKL} {form factor}/{physical layout} without {F-key}s.
7305 - A size/type of {Mill-Max socket}s. Just about identical to the {0305}, but with a shorter tail and lip.
75% - A more compact version of the {tenkeyless}/{TKL} {form factor}, with the arrow and navigation cluster crammed to the right of the {alpha}s.
80% - A {tenkeyless}/{TKL} {form factor} (without the {numpad}). It has 87-88 keys, but the overall width is about 80% of a {fullsize}.
87% @ 80%
96% - A {form factor} with the arrow and navigation cluster moved around to get a more compact {100%}.
100% - The classic {physical layout}, a {fullsize} keyboard.
A* @ A-star
A-star @ Pololu A-star
ABS - A {keycap} material (Acrylonitrile Butadiene Styrene). Gets easier yellow and shiny compared to {PBT}.
ACA @ ant colony algorithm
acoustic cutout - A {cutout} in the {plate} to alter the acoustics of the {case} (in contrast to cutouts for {switch}es).
acrylic - A popular material for {plate}s and {case}s.
Acrylonitrile Butadiene Styrene @ ABS
action code - The 16 bit code generated by a keypress (e.g. in {QMK}). Sometimes used as a synonym for {keycode};
activation force - The pressing force measured at the {activation point} (to register the keypress).
activation point - The {travel distance} required to register the keypress.
actuation force - The pressing force measured at the {actuation point} (to register the keypress).
actuation point - The {travel distance} needed to register the keypress.
add-on kit - A {kit} of a {keyset} other than the {base kit}, covering less conventional {layout}s. See: {extension kit}.
addressable LED - A chain of LEDs where each LED has a microchip that understands a special protocol sent over a single wire (instead of using a wire per color) and the data signal can be passed on.
AHK @ AutoHotKey
Alice - A popular {monoblock} {split} design with {classic staggering}.
all-1u - A {physical layout} with {1u} keys only, e.g. most {ortholinear} and many {split} designs.
all-R3 - An {uniform} {keyset} with exclusively the {R3} keys of a {sculpted} profile.
Alpaca - A {linear} {switch} colored to match the {SA} Bliss {keycap} set with opaque grey {housing} and pink {stem}. One of the first custom colorway ({recolor}) switches.
alpha - The keys belonging to the A-Z letters.
alphabetic layout - A {logical layout} listing {alpha}s in alphabetical order. Used mostly with specialized data entry with one-two fingers (e.g. for pilots in gloves).
Alps - A Japanese manufacturer of {keyswitch}es ({Alps switch}) and other electronic components like {rotary encoder}s.
Alps mount - A non-{MX compatible} {stem} {mount} with a horizontal rectangle.
Alps switch - A discontinued {switch type} by {Alps}. Because of the different {stem} they are not {MX}-compatible. Recreated by Matias ({Matias Alps}).
alternative layout - A non-standard {logical layout} other than {QWERTY}/{QWERTZ}.
angle mod - A modification of the {Colemak} {alternative layout}. The keys along the bottom-left are moved one space to the left.
anodized - A decorative metal finish usually on aluminium {case}s.
ANSI layout - The standard US layout.
ant colony algorithm (ACA) - A mathematical model for {logical layout optimization}.
anti-ghosting - A feature and marketing buzzword hinting at a subset of keys working well together. See {ghosting}.
Arduino - An ecosystem of (often {open source}) {development board}s and {IDE}. E.g. the {Pro Micro} started as an Arduino project.
Arisu - Japanization of the name {Alice}.
Aristotle style stem - A hybrid between a one-piece {clicky} {stem} and a {click jacket} style stem (as seen on vintage Aristotle boards).
ARM - A family of {microcontroller}s introduced by Acron and manufactured by companies like Apple, Samsung, Nvidia etc. See also: {AVR}, {Atmel}
arpeggiating - A method to input more than 6 simultaneous characters on a non-{NKRO} board in {Plover} or {stenography} in general.
artisan - A crafted {keycap} often for the look with limited functionality.
assembled - A keyboard ready to use (in contrast to a {kit}).
Atmega - A family of {AVR} microcontrollers by {Atmel}.
Atmega32U4 - A popular {microcontroller} model by {Atmel} with built-in {HID support}.
Atmel - A company designing and manufacturing {microcontroller}s. Acquired by Microchip Technology in 2016.
Atreus - A characteristic {fixed-angle} {monoblock} {split} keyboard designed by Phil Hagelberg.
AutoHotKey - A popular automation tool running on the host computer. Often combined with rarely used {F-keys} (F13-F24) to fire software/macros on a keypress.
auto-router - A feature of {PCB} designer software to route the {trace}s automatically.
aviator connector - A {detachable connector} like {GX12}/{GX16}, {YC8}, {LEMO} etc., used in custom cables.
AVR - A family of {microcontroller}s developed by {Atmel}.
AVRDude - A (command prompt) software to write various {microcontroller}s of the {AVR} family.
AVRDUDESS - A {GUI} for {AVRDude}.
AWG - The US system of wire gauges.
AZERTY - The default French {logical layout} with the characters AZERTY in the top row.
back plate - The back face of the {stem}.
backlight - Mostly in-switch {LED} light shining through {keycap}s, but the term is also used for {underglow}.
backlit @ backlit keycap
backlit keycap - A {keycap} letting {LED}-light shine through.
bag-lubing - A bulk {lubing} method. E.g. {spring}s and {stem}s put and shaken in a plastic bag with {lube} in it (rather than by manual application with a brush).
band aid mod - A {stabilizer} {mod} to prevent hitting the {PCB} by the stabilizer slider and reduce the rattle.
base housing @ bottom housing
base kit - A {kit} of a {keyset} covering most conventional keyboard {layout}s from {fullsize} to {60%}. See: {extension kit}.
base layer - The default {logical layer} (generally lowercase letters). There can be multiple base layers in a {keymap}.
base plate - The bottom layer of a multilayer keyboard {case}.
battleship - A keyboard with a rather big footprint like a 122-key {IBM Model M}, but even a {fullsize} for some.
battlecruiser - A keyboard with a rather big footprint like a 122-key {IBM Model M}, but even a {fullsize} for some.
beam spring - An old switch type, the grandfather of {clicky} switches. Introduced in the 1970s, their complex capacitive mechanism and space consuming design produces legendary switch feel, but manufacturing costs led IBM to phase them out (source).
BÉPO - A French {alternative layout}: bepo.fr.
big-ass Enter - A large, characteristically shaped Enter {keycap}. (With the Steelseries 6Gv2 as its last holdout (?).)
bigram @ bigraph
bigraph - A character pair. An important element of {logical layout optimization}.
bigraph frequency - The relative (or sometimes absolute) occurrence of {bigraph}s in a {corpus}. An important statistical input of {optimization model}s and {logical layout optimization} in general.
bin - The file extension of the compiled firmware in {bin file} format.
bin file - The {compiled} {firmware} in binary format (ready for {flashing}). More often, the file extension is {hex}.
binning - Throwing out items from the stock (e.g. a manufacturer) that aren't within specific tolerances.
bit bang @ bitbang
bitbang - A protocol and a driver type for LEDs, e.g for {QMK}s {RGB lighting} and {RGB matrix} features (doc).
black pill - An ambiguous name used for various STM32-based {development board}s.
black switch - A heavier {linear} {keyswitch}.
blank - Keycaps without printed, etched or any indication of letters or other symbols on them. See also: {otaku}.
bleeding - The unwanted leaking of {LED} light at backlit {cap}s.
blocker - A placeholder on the {plate}/{case} to cover the unused area. Also: {WKL blocker}
blue @ blue switch
blue switch - A {clicky} {keyswitch}. Blue was the {stem} color of clickies in the original {Cherry MX} lineup.
BluePhage Express - A {development board} with {NRF52840} {controller} supporting wireless keyboards by SouthPaw.
Bluetooth - The most common protocol for wireless keyboards.
board - Reference to a keyboard, {development board} or {PCB}.
Boba @ Boba U4
Boba U4 - A silent {tactile} {switch} by Gazzew with a large, smooth 'D' shaped {tactile bump} with no {pre-travel} (review). Comes with 62g and 68g spring weights.
bolt mod - A {mod} for {IBM Model M} keyboards. Replacing the plastic rivets that hold the keyboard mechanism together with screws and nuts.
bootloader - The "BIOS" of {microcontroller}s which loads the {firmware} when powering up or manages firmware updates.
bootloader mode - The mode to {flash} the keyboard with a new {firmware}. You can enter bootloader mode by {soft reset}, {hard reset} or with {bootmagic}.
bootmagic - A system for configuring the keyboard during initialization (without the need of {flashing}). E.g. entering {bootloader mode}, switching features like debugging, default {layer}s etc.
bottom mount - A {mounting style} securing the {PCB}/{plate} to the bottom frame of the {case}.
bottom out - Pressing a key fully until it can no longer travel, hitting the bottom {housing}.
bottom row - The lowest row of a standard(ish) keyboard with most {modifier}s and the spacebar.
bottoming out @ bottom out
BoW - Black labels on White {keycaps}. A popular color combination.
box stem - The uniquely shaped {stem} of dust-proof {box switch}es by {Kailh}.
box switch - A family of dust-proof switches by {Kailh} (with slightly reduced {wobble}). See: {jade}
bounce - Regular switches report a lot of keypresses for one physical actuation. This noise or bouncing is handled by the firmware (debounce).
bounce time - The time delay needed for the signal to settle or the time the debounce algorithm waits to evaluate the switch state.
breadbin - A high, characteristically rounded vintage {case} design (e.g. that of some C64s).
breathing - A {backlight} effect in {QMK}.
brick - To put a {microcontroller} or keyboard into a terminally unresponsive state (beyond repair). E.g. messing up the {bootloader}.
bricked - Unresponsive {microcontroller} or keyboard due to user error (often beyond repair).
bridge - To use a piece of wire to connect the circuitry broken by a {lifted} {pad}/{trace} on the {PCB}.
brief - Shortcuts in {stenography}. They help to save keystrokes by letting you type fewer {stroke}s to get a word that might otherwise require several strokes.
brown @ brown switch
brown switch - A silent {tactile} {keyswitch}. Brown was the {stem} color of tactiles in the original {Cherry MX} lineup.
bucky bits - The {keycode}/{scancode} bits generated by {modifiers} like Shift, Ctrl, Meta, Hyper, Super.
buckling spring - A {keyswitch} design where the {spring}'s motion is not linear. The spring pivoting the hammer buckles, i.e. collapses, at a certain point, providing auditory and tactile feedback (wiki).
build automation - The process of automating the creation of a software build: compiling computer source code into binary code, packaging binary code, and running automated tests.
build environment - The Linux/Unix based environment to run {QMK} and compile the {firmware}.
build log - A journal of building a keyboard. Probably the greatest source of information for DIY builders (from scratch). (Collection of build logs.)
building - To build a keyboard or build/{compile} the {firmware}.
burger mount - A {mounting style}: {top mount} with {O-ring}s.
CANS - work-related complaints of the arm, neck or shoulder
cap @ keycap
carpal tunnel - The passageway in the wrist where nerves and tendons pass through from your lower arm to your hand (wiki). See also: {carpal tunnel syndrome}.
carpal tunnel syndrome (CTS) - A health condition when the medial nerve is trapped or compressed in the {carpal tunnel}. E.g. because of {wrist extension}, {ulnar deviation} or {forearm pronation}.
cartridge - A removable component as seen on e.g. Giga40 (source).
case - The frame of a keyboard, generally made of plastic, metal or wood. Not every keyboard has a conventional case (sandwich case or caseless).
Caterina - A {bootloader} for e.g. the {Pro Micro}. {QMK Toolbox} or {AVRDude} use this to {flash} the keyboard. See also: {Pololu A-star}.
center hole @ stem hole
center mast - Part of the {bottom housing} where the {center pole} sits in a {switch} and guides the {stem}'s movement.
center pole - Part of the {stem}, keeping it centered.
centi-Newton - A measure of force (with a magnitude similar to {gram-force}), used to characterize switch weight.
charlieplexing - A technique for driving a multiplexed display with relatively few {pin}s on a {microcontroller}. E.g. to drive an array of {LED}s.
chattering - Multiple characters registering in a single keypress. Related to bounce and debouncing.
Cherry - An originally German {keyswitch} and keyboard manufacturer.
Cherry MX - A family of compatible {switch}es with the distinctive "+"-shaped {stem} originally manufactured by {Cherry}.
Cherry profile - A {sculpted}, {cylindrical}, relatively low {keycap profile} by {Cherry}. E.g. {GMK} keycaps come in this profile.
chicklet - A keyboard with small, flat rectangular rubber or plastic keys. An evolution of the {membrane} keyboard (wiki).
chip @ integrated circuit
Choc @ Kailh Choc
chord - A key combination pressed simultaneously. See: {stenography}.
chording - Pressing multiple keys simultaneously to achieve higher typing speeds. See: {stenography}.
CircuitPython - An {open source} version of MicroPython for {microcontroller}s (git). See also {KMK} firmware.
classic staggering @ horizontal staggering
clean time - The time required by the {debounce algorithm} for a signal to settle before triggering a keypress.
click bar - A mechanism to produce the sound of a {clicky} {keyswitch}.
click jacket - A mechanism to produce the sound of a {clicky} {keyswitch}. E.g. in a Cherry {blue}.
clicky @ clicky switch
clicky switch - A {tactile} {switch type} with auditory feedback (click).
clip mod - A {mod} clipping the parts the {stabilizer} insert ({stem}) to reduce wobble.
clipping @ clip mod
cloud of boobs - A reference to the sensitivity of {Cherry} {red} {switch}es, light {linear} switches in general and a typing style. Coined in 2013, in the early years of {r/mk} (source).
cN @ centi-Newton
CO2 laser - For {laser cutting} non-metal materials, e.g. {acrylic}.
cold joint - A {soldering} failure.
Colemak - A popular {alternative layout} (more).
Colemak-DH - A popular modification of the {Colemak} layout (more).
columnar staggering - The arrangement of keys in vertically shifted columns (contrary to the classic {horizontal staggering}).
compile - To turn the human-readable source code into binary code. See: {build automation}
compiled - Turned into compact, computer-readable binary format.
complex spring - A hybrid {spring} starting out as a {linear spring} but transitioning to a {progressive string} part way through the keypress.
component @ electronic component
Compose - Not a {modifier} but a {dead key}.
connected coils - A parameter of a {spring}.
connector type - See: {DIN}, {PS/2}, {USB micro}, {USB C}.
contra-lateral - Keying opposing letters of the two hands, e.g. S-L, D-K, F-J on a standard {QWERTY} {layout}.
controller - An ambiguous reference to a {microcontroller} or {development board}.
converted - A restored vintage keyboard usable with today's operating systems, often with a new {controller} but keeping the {matrix}.
converting - Turning a vintage keyboard into a USB-one, often with a new {controller} but keeping the {matrix}.
copper - The material of {PCB} {trace}s or some keyboard {plate}s.
copper plane - The layer of copper in the sandwich material of a {PCB}.
copper weight - {PCB}s are manufactured in different layer thicknesses. Copper weight is the term used to describe this thickness. It's measured in ounces.
corpora @ corpus
corpus (pl. corpora) - A bunch of text for language statistics and {logical layout optimization}.
Costar stabilizer - A {stabilizer} type that hooks into the {keycap} and clips into the stabilizer in contrast to the more common Cherry style one.
cream - A {linear} {switch} made entirely from {POM} (both the {stem} and {housing}). The first one of this kind. Announced by Novelkeys in August 2018, manufactured by {Kailh}. Known from its fishy smell (source).
cross-mount - The traditional {MX compatible} {mount}.
CTD @ Cumulative Trauma Disorder
CTS - See: {carpal tunnel syndrome} or {cubital tunnel syndrome}
cubic - A {sculpted} {cylindrical} {keycap profile} by {Tai-Hao}.
cubital tunnel - The passage at your elbow the ulnar nerve is passing through. See: {cubital tunnel syndrome}
cubital tunnel syndrome (CTS) - A condition that causes pain throughout the hand due to pressure on the ulnar nerve when the elbow is bent.
cumulative trauma disorder - One of the many keyboard related health issues.
cutout - The various shapes of rectangles in a plate you put the switches in. The most basic being the 14x14mm square cutout.
cylindrical (keycap) - A {keycap} profile with a cylindrical well on the top (contrary to a {spherical} one).
D-sub - An electrical connector with D-shaped metal shield. E.g. the 9-pin one for serial connection.
D-sub 9 - An electrical connector for serial communication with D-shaped metal shield and 9 pins. Also known as {DE-09}.
D-subminiature @ D-sub
Dactyl - A characteristic {split} keyboard with 3D plate and {keywell} by Matt Adareth (git).
dampening @ sound dampening
data input (Din) - A wire of e.g. a {LED} strip to provide data to the driver chips.
data sheet - A short documentation of an electric component, e.g. controller, rotary encoder, diode.
Datahand - A weird input device limiting finger motion. Created in the 1990s by Dale Retter.
DE-09 @ D-sub 9
DE-9 @ D-sub 9
debounce - The {firmware}'s method to handle the {bounce} of {switch}es when actuating.
debounce algorithm - The algorithm of the {firmware} deciding when a signal should be registered as a keypress or handled as noise.
debounce delay - A parameter of the {debounce algorithm} waiting for state changes (resulting in a small {lag}).
DEC - Digital Equipment Company was a manufacturer of computers and inventor of the arrow cluster seen on the {standard keyboard} ({inverted T}).
deep dish - One way to indicate homing keys, especially on SA keycaps (as opposed to homing dots/dashes).
defer - A debounce method in QMK. PhysicalDebounce(3-5ms) + DEBOUNCE(5ms). Noise lasting less than 5ms will not trigger keypresses.
dent - Feature of a {rotary encoder} making it tactile.
dented - A tactile {rotary encoder}. In contrast to a linear encoder.
design rule check - One of the last steps of {PCB} design. Running this check tells you if any components overlap or if {trace}s are routed too close together. Items that fail the design rule check are listed in the "DRC Errors" folder.
deskthority - A community and site dedicated to mostly vintage keyboards, restoration and converting.
development board - A {microcontroller} on a piece of {PCB}, surrounded by the necessary electrical components. E.g. {Pro Micro}, {Elite C}, {Proton C}.
desoldering - Removing a soldered component from the {PCB} or {circuit}.
desoldering pump - A tool to suck the melted solder material while {desoldering}.
detachable connector - A connector designed to be, well, detachable. Colloquially referred to as {aviator connector}.
detent - An attribute of {rotary encoder}s. No detents: smooth, detents: tactile.
DFU mode - Device Firmware Update or {bootloader mode}.
dielectric grease - A type of {lube}, usually applied on the metal-plastic (wire) contacts of {stabilizer}s.
DIN - The German institute of standards, and an old, thick, pre-USB {connector type}, or the abbreviation/caption for {data input}.
diode - The one-way valve in electronics. Conducting electricity in one direction only.
diode direction - The direction {diode}s face, usually marked by a black ring. In the {matrix}: row to column or column to row direction.
DIP switch - A type of switch array (Dual In-line Package), generally used for basic hardware configuration (wiki, doc).
DIY - Do It Yourself. A handmade keyboard or {kit} that needs {soldering} or manual assembly (as opposed to a pre-made or {assembled} one).
dogbone - A cutout technique to get corners with a round router/cutting tool. (Hole on a corner.)
dome - Bumps on the {membrane} of a {rubberdome} keyboard or the similar separate part of e.g. a {Topre} or {prototopre} {switch}.
double-shot - Keycaps molded with two different colors. Requires a mold for the external shape and another one for each legend, which makes this technique expensive.
DRC @ design rule check
DSA - An {uniform}, {spherical}, {sculpted} {keycap profile}.
DSK - The {Dvorak} Simplified Keyboard.
dummy stem - An old solution to stabilize larger than {2u} keys (before {stabilizer}s).
duplex matrix - A creative arrangement of keys in the {matrix} to spare on {pins} of the {controller}. Connecting {switch}es of two columns in a U-shape.
Durock - A {switch} manufacturer.
dustproof mount - The partially closed {cross-mount} or the box-style {mount} of some {Kailh} {switches}.
Dvorak - An extensively researched {alternative layout} designed by {Dvorak, August}.
Dvorak, August (1894-1975) - Inventor and advocate of the {Dvorak} {alternative layout} (wiki).
Dvorak Simplified Keyboard - The original name of the keyboards/typewriters with the {Dvorak} layout.
DXF - A vector file format for e.g. {plate}s, used for {laser cutting}. Similar to {SVG}. See: {plate generator}, {plate builder), {KLE}.
dye-sub @ dye-sublimated
dye-sublimated - A {legend} printing method. The ink is heat-and-vacuum printed inside the plastic. The pigment becomes part of the keycap. Usually darker legend on lighter {keycap}.
dynamic macro - A {macro} recoded on the keyboard, which will be lost when the keyboard is unplugged.
Eager - A {debounce} method: 0ms input lag from contact point, then blocks changes for DEBOUNCE(5ms). Noise is reported as a keypress.
EC11 - A popular {rotary encoder} type/dimension.
Eclipse - A popular {IDE} for developing in C.
EEPROM - Permanent storage of the {microcontroller}. E.g., used to set {handedness} for {split} keyboards (doc).
electronic component - The puzzle pieces of a circuitry, e.g. switch, resistor, capacitor, diode.
Elite C - A type of {Pro Micro} clone {development board} with {USB Type C} connector.
encoder @ rotary encoder
endgame - The mythical ultimate setup.
ePBT - A {keycap} manufacturer. Used to dye-sub {Gateron} {PBT} caps but they use their own caps now.
ergo - {ergonomic} keyboard
ergo kit - A {keyset}'s {kit} covering {ergonomic} layouts, e.g. including symmetric {modifier}s and {thumb key}s for an {ErgoDox}.
ErgoDox - An early {ergonomic} {split} keyboard design with {thumb cluster}.
ergonomic - Designed according to the rules of {ergonomics}: with health and productivity in mind.
ergonomics - The applied science of designing tools with health and productivity in mind.
evolutional model - A mathematical model for {logical layout optimization}. See: {population size}, {generation}, {evaluation algorithm}
evaluation algorithm - The algorithm which evaluates layouts and generates a score in {evolutional model}s and {logical layout optimization}.
exposed switches - A {low profile} {case} design where {switch} {housing}s are exposed.
extension kit - A {kit} of a {keyset} to cover more exotic layouts like {split}s and {40%}s. See: {base kit}.
extras - After a successful {GB}, an additional number of the product can be manufactured (above the final pre-order number) to account for later {QC} issues or if the vendor wants to sell them from stock.
F-key @ function key
F-row - The row of the {function key}s.
F10 - A {uniform} flat (neither {cylindrical} nor {spherical}) {keycap profile}.
faceplate - The top plate usually holding (or covering) the {switch}es.
fibre laser - For the {laser cutting} of metal {plates}.
film - The thin layer of adhesive film cut to the shape of a switch housing to alleviate housing wobble and/or change sound.
filming - The method to counter housing wobble by putting a thin layer of adhesive film between the top and bottom housing.
firmware - The software running on the keyboard when powered up, e.g. {QMK}, {TMK}, {ZMK}, {PRK}.
fixed-angle - A one-piece {split} keyboard where the halves' {slant angle}/{opening angle} is fixed.
flash @ flashing
flashing - The process of writing the {firmware} on the {microcontroller} (in {bootloader mode}).
flex cut - Additional cuts in the {plate} (beside {switch} {cutouts}) for added flexibility.
flipping - Buying a (limited) product and selling it for profit.
floating PCB - A {mounting style} where the {PCB} has no bottom support and is held in place only by ({plate mounted}) {switch}es.
Fn - Not really a {modifier} but a hardware key that's not directly interfaceable by the {OS}. The OS can't detect whether Fn is pressed or not.
foam - A {dampening} material.
foam and foil - An old {switch} type by e.g. Alphameric and Keytronic. With a foil disk and conductive foil at the {stem} end pushing onto the {PCB} during a keypress.
foaming - Dampening the {case} with {foam} to mitigate reverb and hollow sound.
force curve - A graph representing {switch weight}/force as a function of {travel distance}.
forearm pronation - The angle or range of lateral inclination of the forearm with your palm facing the desk (contrary to {forearm supination}).
forearm supination - The angle or range of lateral inclination of the forearm with your palm facing upwards (contrary to {forearm pronation}).
form factor - A specific type or group of {physical layout}s, often expressed in a percentage relative to the {fullsize} keyboard (100%) (uni).
FR4 - The fibreglass material of {PCB}s, a glass-reinforced epoxy laminate material, used as a {plate} material too. "FR" stands for "flame retardant" (wiki).
frankenswitch - A {switch} put together from parts of different switch models, mixing their characteristics.
front plate - The front face of the {stem}.
frosted - Used mostly for opaque acrylic.
fullsize - The classic keyboard {form factor} with {F-key}s, numpad, navigation and arrow cluster.
function key - The F1-F12 keys in the top row of the {standard keyboard}. Up to F24 on some vintage keyboards.
function layer @ layer
G20 - An {uniform}, flat top {keycap} profile from {SP} suggested for regular keyboards used as {steno machine}s.
gable - tenting (in earlier research papers)
gasket - The material (e.g. neoprene, poron) used in a {gasket mount} {case}.
gasket mount - A {mounting style} using gasket material between the {plate} and keyboard case on both top and bottom housing, resulting in a more cushioned feel compared to the {sandwich mount} design.
Gateron - A {keyswitch} (and {keycap}) brand and manufacturer.
Gateron Yellow - An all-time classic {linear} {switch} with a debut sometime in 2014.
GB @ group buy
GB runner - The organizer of a {group buy}.
geekhack - A forum style community site at geekhack.org. The starting point of many {IC}s and {GB}s.
generation - A cycle of an {evolutional model}. New layouts are generated ({population size}}, evaluated ({evaluation algorithm}) and ordered to kill the poor ones.
genetic model - A mathematical model for algorithmical optimization for the logical layer.
Gerber files - A set of files containing the necessary info to manufacture a {PCB}.
gf @ gram-force
GH @ geekhack
ghetto browns - Modded {blue}s without the clicky sound (details).
ghetto red - black {stem} + brown {spring}
ghetto white - brown {stem} + black {spring}
ghosting - Registering of a phantom keypress (due to inadequate matrix or firmware design). The term is often confused with {jamming}.
GIO pin - General Input-Output Pin (of a microcontroller).
git - A command line versioning software.
GitHub - An online place to store and track {git} projects, e.g. {QMK}.
giveaway - A promotional tool used to improve awareness of a brand, improve the company's image or drive sales.
GMK - A German {keycap} manufacturer known for its {Cherry profile} {keyset}s.
GND - Ground.
GPIO pin - General Purpose Input-Output pin. Their number defines the number of keys in a keyboard {matrix} and as such is one of the most important parameters of a {microcontroller}/{development board}.
GPL grease - General Purpose Lubricant. A form of synthetic industrial lubricant (also for lubing keyswitches), e.g. Krytox.
grab bag - A random mix of keycaps often with quality issues and sold by the weight.
gram-force (gF) - A common unit of keyswitch weight, similar to {cN} (centi-Newton).
grave escape - A {firmware} feature to share Escape and "`" plus its shifted "~" on the same key (doc).
group buy - A form of pre-financing or fundraising where buyers pay for a product prior to manufacturing.
GUI - Graphical User Interface. E.g. {QMK Configurator} for {QMK}, {AVRDUDESS} for {AVRDude}.
GUI key - The Win/Command {modifier} depending on the system.
GX12 - A cheap type of {detachable connector}s with a 15mm diameter at its thickest point. 5mm for the cable may be too thin and squeeze it or the {heat shrink}/{sleeving}.
GX16 - A cheap type of {detachable connector}s. This one may be too bulky (18.5mm max diameter) and may leave a gap as the cable leaves the connector.
half plate - A {plate} with removed {alpha} cluster for reduced stiffness. Only for {PCB mounted} {switch}es.
Hall effect - A contactless technology where a magnet passes by a sensor that registers the keypress based on the proximity. 30 billion keypress lifetime.
handedness - A parameter of {split} keyboards. Required for the {firmware} to decide which half is which (doc).
handwired - A keyboard without a {PCB}, soldered and wired up manually.
handwiring - The method to wire up a keyboard without the need of a {PCB}. Cheap but tedious. Used for prototyping or for 3D boards like a {Maltron} or {Dactyl}.
hangul - The Korean alphabet. A separate {kit} in some {keyset} {GB}s.
hard reset - Resetting the {controller}/{development board} by {shorting} the {RST} and {GND} {pins} (contrary to {soft reset}).
Hansen Writing Ball - The first commercially produced typewriter (1870) invented by Rasmus Malling-Hansen in Copenhagen (wiki). Overtaken in the market by the {Sholes and Glidden typewriter}.
heatshrink - A tube contracting on heat. It comes in several diameters to cover and seal otherwise exposed parts of e.g. a custom cable.
heavy switch - A {keyswitch} with a {weight} on the more heavy side of the spectrum.
hex - The file extension of the compiled firmware in {hex file} format.
hex file - The compiled {firmware} in binary format (ready for {flashing}). Sometimes the file extension is {bin}.
HHKB layout - A keyboard and {physical layout} without the corner keys on the {bottom row}. Designed by {Wada, Eiiti} in 1996 (interview).
HID - Human Interface Device. An USB technology to support a low latency, low power link to devices like a mouse or keyboard.
HID support - The feature of recognizing a keyboard as an actual keyboard device without the need of extra circuitry. That's what made the Atmega32u4 a popular choice for keyboard builders.
hiragana - One 'alphabet' (phonetic lettering system) of the Japanese language. The more curvy one. Popular on {keyset}s. See also: {katakana}, {kana}.
hold - Pressing and holding a key, e.g a {modifier}. In contrast to a {tap}.
Holy Panda - A legendary {tactile} {frankenswitch} discovered by Quakemz. A Halo True or Halo Clear {stem} put into an Invyr {housing}. See: {pandaverse}
Holy Trash Panda - A Trash Panda {switch} with the stock {stem} replaced by a Halo True/Clear stem.
home box - A specific area of the {keymap} for keyboard layout evaluation/optimization. (See also: {home row})
home positions - The keys your fingers rest on: ASDF - JKL; on a standard English {QWERTY}. The positions of the index fingers (F/J) are indicated by homing dots, dashes or deep dish.
home row - The middle row of the keyboard where your fingers rest.
homing - Proper positioning or repositioning of your hand on the keyboard. E.g. index fingers on F/J on a {standard keyboard}.
homing bar - The bar-shaped mark on the {homing keys} F/J.
homing bump - The mark on the {homing keys} F/J.
homing dash - The mark on the {homing keys} F/J.
homing dot - The dot-shaped mark on the {homing keys} F/J.
homing edge - The {homing} solution of {MBT} {keycap}s.
homing keys - Keys with a marking (e.g. {homing bump}, {homing dash} or {deep dish}) to help repositioning your index fingers. Usually F and J on a {standard keyboard}.
horizontal staggering - The classic {staggering}, a legacy of the mechanical typewriters.
host - In relation with your keyboard the host is usually your computer. See also: {USB host}.
hotswap - Removable/replaceable (especially {switch}es, but e.g. also {LED}s).
hotswap socket - A socket (soldered on the PCB) to allow solderless replacement of keyswitches.
hotswap PCB - A PCB with onboard hotswap sockets.
housing - The plastic outer shell of a keyswitch.
housing pole - The tiny vertical pole-shaped part of the {bottom housing} the {spring} is sitting on.
housing wobble - Movement of the upper {housing}. May be aggravated by the frequent opening of the switch. Mitigated by {filming}.
hunt-and-peck - An inefficient method of typing in which one looks at the keyboard and types usually only with the index fingers (contrary to {touch typing}).
hurdle - Row jumps (e.g. skipping the {home row}) while typing as referred to by August {Dvorak} in his works. E.g. there are 6 hurdles/row jumps while writing the word 'minimum' on a standard QWERTY layout.
hydrogen peroxide - A chemical used to {retrobright} plastic parts.
Hyper - A {modifier} introduced on the {space-cadet} keyboard. Emulated by the combination of left Control, Shift, Alt and {GUI key} in {QMK} and other {firmware}s.
hysteresis - The gap between the {actuation point} and {reset point}. Most switch reset points are higher than the actuation point, so a key has to be released almost fully in order to reset for the next press, which can make double-tapping and rapid same-key typing difficult.
I/O pin - The general input/output pins of a microcontroller to read or send voltage/electric signals.
I2C - A way to chain electric components, e.g. {LED}s or halves of a {split} keyboard.
IBM Model M - A legendary vintage keyboard model with a distinctive click and feel.
IC - Abbreviation for {interest check} or {integrated circuit}.
IDE - Integrated Development Environment, e.g. Arduino IDE.
input latency - The delay between actuation and registration of a keypress by the microcontroller/OS.
integrated circuit - A bunch of electronic {circuit}s with a tiny {footprint}. See: {microcontroller}, {AVR}, {Pro Micro}. (wiki)
integrated plate - The {plate} is part of the (usually top) {case}. Associated with poor acoustics, switch {wobble} and hard {bottom out}.
interest check - A step before the group buy or fund raising phase. The community is polled regarding an upcoming product.
intuitive optimization - Arranging the keys based on common sense. This is inefficient or even counterproductive compared to a more complex {evaluation algorithm} or {model}, since too many factors are involved to keep them all in mind to evaluate.
invader - A {bottom row} with a gap between Ctrl and Alt.
inverted T - The common arrangement of the arrows on a {standard keyboard}, invented at DEC.
intensity value - A value to characterize the light emission of an {LED}. Expressed in {millicandella} [mcd].
IO expander - An {IC} providing a simple solution when more {GPIO}s are needed. Communicating through serial or {I2C} they are used e.g. for the {slave} half of a {split} (instead of another {controller}).
IP30 - Non-waterproof. The protection class provided by the bare LED strip agains water (2.13mm thickness).
IP56 - Dust-proof, based on the standard rating the protection provided by casings against dust and water (e.g. {Kailh} {box switch}es).
IP65 - Waterproof. A protection class, e.g. the protection provided against water by an {LED strip} with silicone coating (3mm thickness).
IP67 - Waterproof. A protection class, e.g. the protection provided against water by an {LED strip} in a silicone tube (3.85mm thickness).
iron @ soldering iron
ISO layout - A common {physical layout} used in Europe.
ISP - In-system programming. A method to program an {AVR} chip using external hardware and the {JTAG pin}s.
Iv @ intensity value
jack - The female connector for a {TRRS} cable, usually to connect separate {split} keyboards.
jade @ Kailh Box Jade
jailhouse mod - Locking down the click jacket on a blue switch so that it can't move. This eliminates the click and halves the {travel distance} at the {actuation point}.
jamming - A pressed key not registering due to inadequate {matrix} or {firmware} design. Also, the intentional suppression of a keypress (to prevent {ghosting}).
JLPCB - A popular {PCB} manufacturer for ordering keyboard PCBs.
JSpacer - A replacement for the wire when {jailhouse mod}ding.
JTAG pin - An industry standard interface for verifying designs and testing {PCB}s after manufacture.
JTK - A {keycap} manufacturer.
JWK - A {switch} manufacturer.
Kailh - A Chinese switch manufacturer.
Kailh Box Jade - A very loud and {tactile} {switch} with light green (jade) stem.
Kailh Choc - A type of {low profile} {switch}es and {keycap}s by {Kailh}.
Kailh Cream @ {Novelkeys Cream}
kana - Japanese writing systems and a special key with {LED indicator} to switch between them. See: {hiragana}, {katakana}.
KAT - A {sculpted}, {spherical} {keycap} profile.
katakana - One 'alphabet' (phonetic lettering system) of the Japanese language. The more blocky, cleaner one. Popular on {keyset}s. See also: {hiragana}, {kana}.
KB2040 - A {development board} by Adafruit with {Pro Micro} footprint featuring the {RP2040} chip. Also known as {Keeboar}.
KATE - A new {doubleshot}, {sculpted}, {cylindrical} {keycap profile} by RAMA. Not available yet. (source)
keeb - Keyboard.
Keeboard - A {development board} by Adafruit with {Pro Micro} footprint featuring the {RP2040} chip. Also known as {KB2040}.
kerf - The material burned away by the machine ({laser cutting}). Usually, 0.15-0.2 mm. To account for the kerf, the paths have to be offset by the amount of the kerf.
key bounce - The erratic behaviour of a switch at actuation, bouncing between on and off states many times before settling on ON. Handled by the {firmware}'s {debounce algorithm}.
key rollover - The maximal number of keys pressed at the same time and still registered by the {microcontroller}/keyboard.
key unit - A single-width key (e.g. an {alpha}) used as a measure of key size.
Keyboard Layout Editor - An online tool to design or visualize keyboard layouts. Its {raw data} serves as input for many other tools, e.g. the {plate builder}.
keyboard matrix - The gridlike arrangement of keyswitches into rows and columns to handle more switches than {I/O pin}s on the {controller}.
keycap - The plastic part on top of the {switch} you actually touch. Comes in different {profile}s.
keycap mount @ mount
keycap profile - The shape and height of the {keycap}. Can be classified into {uniform} and {sculpted}, {spherical} and {cylindrical}, or by keycap height ({low profile}). (keycaps.info)
keycap puller - A tool to remove keycaps from the switches.
keycap sprue - In {keycap} casting, the passage through which the molten material is introduced into the {mold}. Also, the associated hole or excess plastic which solidifies in this passage.
keycode - Used ambiguously. E.g. the lower 8 bits of the action code, or generally the identifier of a key used in {keymap}s by the {firmware}. E.g. in {QMK} it's usually the {scan code} preceded by 'KC_'.
keymap - The (code describing the) arrangement of characters/functions in a {logical layer}, e.g. an array of layers in one of {QMK}'s C files.
keyset - A {keycap} design with specific {profile} and colorway available for purchase. Often broken down into {kit}s.
keyswitch - The individual switches residing under the {keycap}s of a {mechanical keyboard}. They come in different types, colors and weights.
keytopper - Keys you can stick on your keyboard to mimic a {steno machine}.
keywell - A 3D, sculpted plate introduced by {Maltron} and used on keyboards like {Kinesis} and {Dactyl}.
kit - A subset of a {keyset} or a set of parts necessary to build a keyboard, sold together (usually, without switches and {cap}s).
kit compatibility - A {keyset}'s coverage of keyboard {layout}s.
KLE @ Keyboard Layout Editor
KLE raw data - A JSON string generated by {KLE} and used by many tools as input.
KMK - A {firmware} using {CircuitPyton}. A framework to easily write portable {makefile}s and drag&drop firmware update instead of the arduous workflow and {flashing} with {QMK}.
Knight keyboard - Used with the MIT-AI lab's bitmapped display system, designed by Tom Knight (~1970) (wiki). Predecessor of the {Symbolics space-cadet} keyboard.
KPS - Keypress Per Second. Not really a {typing speed} measure, rather one for typesetting machines.
KPH - Keypress Per Hour. See: {WPM}
KPM - Keypress Per Minute. See: {WPM}
Krytox - A family of lube products.
Krytox 204g0 - A {lube} generally used for switches, thinner than {Krytox 205g0}.
Krytox 205g0 - A {lube} generally used for switches, thicker than {Krytox 204g0}.
language layout @ logical layout
layer - A set of characters/functions of the {logical layout} accessed by {modifier}s.
layout - The physical or logical arrangement of the keys of a keyboard.
layout optimization - The intuitive or algorithmic process to effectively arrange the keys/functions of a keyboard.
laser @ laser cutting
laser cutting - The way to manufacture plates or layered cases, but also involved in {PCB} manufacturing. Cutting metal requires {fibre laser}, but other materials ({acrylic}) can be cut with cheaper {CO2 laser}.
laser etching - A method to print {legend}s on a {keycap}. Also, legends can be etched into a fully dye-subbed keycap to let light shine through ({backlit keycap}s).
latency - The delay between actuation and registration of the keypress (by the {microcontroller}/OS).
lateral inclination @ tilting
Leader key - A feature and special {modifier} key in {QMK} to allow a sequence of keypresses to be handled as a simultaneously pressed key combination (wiki).
leaf @ metal leaf
LED - Light-Emitting Diode. A {diode} producing light. Used for {LED indicator}s, {underglow}, per-key lighting.
LED indicator - {LED}s defined in the {HID} specification to indicate layer status: Num Lock, Caps Lock, Scroll Lock, Compose, {Kana}. See also: {lighting layer}
LED slot - The cutout in the {upper housing} for the per-key {LED}.
leg - The tiny pieces/pins on the {upper housing} used to attach it to the {bottom housing}. 4 pins or {winglatch} style. Or the little slanted legs of the {front plate} of the {stem} which interacts with the {leaf}.
legend - The writing on the {keycap}.
LEMO - A more expensive type of {detachable connector} used in custom cables.
letter frequency - A statistical parameter of a text or language representing the relative occurrence of letters.
letter layout @ logical layout
levitator - A magnet mechanism in a {Hall effect} {switch} to ensure {springless} {keycap} depress.
lifted trace - A common problem of {hotswap} {PCB}s, where pushing of the {switch} lifts or breaks the conductive copper path. You can fix it by soldering or with a wire bridge.
light switch - A {switch} with a {switch weight} in the lower range.
lighting layer - A {firmware} feature to indicate layer status by {underglow} as normally {LED indicator}s do (doc).
linear - See: {linear switch} or {linear spring}
linear spring - A {spring} providing a linearly increasing force throughout the keypress.
linear switch - A {switch type} without any tactility or intentionally produced sound. Preferred by gamers.
logical layout - The arrangement of letters/characters/functions on the physical keys. See: {alternative layouts}
logical layout design @ logical layout optimization
logical layout optimization - Researching the optimal arrangement of the keys by {intuitive optimization} or by mathematical models. See: {evolutional model}
low pro @ low profile
low profile - A {keycap}, {switch} or keyboard with a relatively low height. Generally, a low profile may help to mitigate {wrist extension}.
lube - A lubricant applied on {switche}s ({stem}s, {spring}s) and {stabilizer}s.
lubing - The action of lubricating the {switch} {stem}s, {spring}s or {stabilizer}s.
M2 - A screw and spacer size with a thread diameter of 2 mm.
M3 - A screw and spacer size with a thread diameter of 3 mm.
macro - A {firmware} feature allowing to send multiple keystrokes when pressing a key (to type common phrases, repetitive game movements, code fragments, etc.).
macropad - A tiny board with a few {switch}es and/or {rotary encoder}s.
Make (software) - A {build automation} tool that automatically builds executable programs from {source code} by reading files called {makefile}s which specify how to derive the target program.
makefile - A file (by default named "Makefile") containing a set of directives used by a {make} {build automation} tool to generate a target/goal.
Malt, Lillian - Inventor of the {Maltron} {ergonomic} keyboard and its custom {logical layout} ({Maltron layout}).
Maltron - A family of {ergonomic} keyboards designed by {Malt, Lillian} (1977) and a company by the same name.
Maltron layout - An {alternative layout} designed by {Malt, Lillian} in 1977, with the letters ANISF and DTHOR on the {home row} (wiki).
master - The separate {split} half with direct USB connection to the PC (contrary to the {slave}).
Matias Alps - A recreation of the {Alps} {keyswitch} available here.
matrix - See {keyboard matrix} or {matrix layout}.
matrix layout - An old (well, around mid 2010s) expression for {ortholinear}.
MBK - A {uniform}, {low profile} {keycap} designed by u/mburger89 and manufactured by u/fk-caps.
mcd @ millicandella
MCU @ microcontroller
MDA - A {sculpted}, {spherical} {keycap} profile.
MDPC-X - A German manufacturer of high quality and relatively expensive cable {sleeving}.
mech @ mechanical keyboard
mech meetup @ meetup
mechanical keyboard - Generally, a keyboard with a {keyswitch} under each {keycap} (in contrast to a {rubberdome}, {membrane} keyboard).
meetup - An event organized by and for keyboard enthusiasts. A good way to try out boards, {cap}s, {switch}es and make friends.
membrane @ membrane keyboard
membrane keyboard - A cheap keyboard type without individual {keyswitch}es.
Meta - A {modifier} on some vintage keyboards, e.g. the {Symbolics space-cadet}. Equivalent to Alt on later keyboards. Equivalent to the {GUI key} (Win/Command) in {QMK}.
metal leaf - The part of a {switch} sitting in the {bottom housing} and closing the electric {circuit} when the {stem} gets pushed into it.
microchip @ integrated circuit
microcontroller - A tiny self-contained computer on a chip. An {integrated circuit} with processor, memory, storage etc. running the {firmware}, handling keypresses and communicating with the {OS}.
mid-mount - Something mounted in the middle (in contrast to on top) of the {PCB}. E.g. an USB connector.
mil - A measurement that equals 1/1000th of an inch, i.e. 0.001 inch or 0.0254 mm. Often used in {PCB} design.
Mill-Max @ Mill-Max socket
Mill-Max socket - A {socket} type, especially for {socketing} {switches}. Common models: {0305}, {0705} and {0279}.
millicandella - The measure of intensity value ({Iv}) of an {LED}. Abbreviated as {mcd}.
minimum order quantity (MOQ) - The quantity of orders a {group buy} has to meet or the manufacturer prescribes for the product to go into production.
Miryoku - An {ergonomic} {logical layout} for various {physical layouts} maintained in emacs org-mode tables and converted to {QMK} {keymap} data structures (git).
mod - Modification like {lubing}, {filming}, {spring swap}ping etc.
Mod-DH @ Colemak-DH
mod-tap - A key MT(mod, kc) acting like a {modifier} when held and a regular key when tapped.
model @ optimization model
model M @ IBM model M
modifier @ modifier key
modifier key - A key to switch between {logical layer}s i.e. set of characters or functions. On a {standard keyboard} switches like Shift, Ctrl, Alt. However, with {QMK} you can turn any key into a modifier.
mold - In {double-shot} {keycap} manufacturing the (many) CNC milled metal parts the plastic is injected into. Or a similar device for resin casting.
monoblock - A non-separate, usually {fixed-angle} {split} keyboard. E.g. the {Atreus}.
monoblock split - A non-separate, usually fixed-angle {split} keyboard.
mount - The top part of the {stem} protruding out of the {upper housing}'s {center hole} where the {keycap} is mounted. E.g. the '+'-shaped part of an {MX compatible} stem.
mounting @ mounting style
mounting post - The part of the {case} for screws. See: {tray mount} {mounting style}.
mounting style - The way of securing a {PCB} or {plate} in the {case}. E.g. {gasket mount}.
mousekey - Keys/functions that let you control your mouse (cursor movement and clicks) by keypresses.
MOQ @ minimum order quantity
MSD - musculoskeletal disorders
MSD-UE - musculoskeletal disorders of the upper extremities
MSYS2 - A {build environment} for Windows. Necessary to run {QMK} on Windows. Available at: msys2.org.
MT3 - A {sculpted}, {spherical} {PBT} {keycap} profile by matt3o. Similar to {SA}, but lower.
muscle memory - Repetitive movement creates a long-term memory for that motoric task, allowing it to be performed without conscious effort. See: {touch typing}. (wiki)
MX - A family of {keyswitch}es originally manufactured by {Cherry}.
MX-compatible - A {keycap} fitting on the "+" shaped {MX stem} of a {switch} (but not on {Alps}, {Topre} or some {low profile} switches).
MX stem - The characteristic "+"-shaped {stem} of the {MX switch}es.
MX switch - Original MX switches by Cherry, as well as MX-compatible switches by other manufacturers.
N-key rollover - The ability of a keyboard to correctly report any number of simultaneous keypresses. Because of the {USB standard} this is restricted to 6 keys in many keyboards, but there are ways to boost this.
nameplate - The area for branding on the {upper housing} of a {switch}.
NC @ normally closed
negative slope - When the top plane of the keyboard is (the {keycap}s) are facing away from you. In general, this is more {ergonomic} than a {positive slope} by mitigating {wrist extension}.
Neo - A German {alternative layout}.
neoprene - A material used for {sound dampening} and as {gasket} material.
new old stock - An unused vintage keyboard. Old but like new.
NRF52 - A family of {microcontroller}s for wireless keyboards.
NRF52840 - A {microcontroller} with Bluetooth support for wireless keyboards.
nice!nano - A {development board} to replace {Pro Micro} for wireless projects.
NKRO @ N-key rollover
NO @ normally open
NorDe - An {extension kit} of a {keyset} with accented letters to support German and Nordic languages.
normally closed - A {switch} with ON as the default state (closed {circuit}). A keypress breaks the circuit. Mostly for safety switches.
normally open - A {switch} with OFF as the default state (broken {circuit}). Most push-buttons and keyswitches. A keypress closes the circuit.
non-standard bottom row - Modifiers with various widths (contrary to the uniform {1.25u} {modifier}s of a standard {bottom row}).
north-facing - E.g. a {switch} with the {LED slot} in the back.
NOS @ new old stock
Novelkeys Cream @ cream
novelty - A {keycap} with a symbol/artwork often related to a {keyset} theme (rather than a letter or usual symbol).
NP - A {uniform} {keycap profile}, similar to {XDA}. Also known as PG.
numpad - The area with the numbers and arithmetic symbols on the right of a {standard keyboard} or as a separate board.
O-ring - A silicone ring affecting sound ({sound dampening}), feel and used to shorten key {travel distance}.
OCD @ Occupational Cervicobrachial Disorder
Occupational Cervicobrachial Disorder - A group of keyboard related health issues affecting the neck and arm.
OEM - A {sculpted}, {cylindrical} {keycap} profile. Often the default profile of stock keyboards.
OLED - Organic {LED}.
OLED display - A device to display {layer} and branding info, logos, animations. Usually communicating over {I2C} (doc).
OLED module - An {OLED display} with all the necessary electronic components on a tiny {PCB}, ready to wire up.
one shot modifier - This {firmware} feature activates a {modifier} until the next keypress only. E.g. to prevent ill-timed Shift usage and to capitalize the next letter only.
one shot layer - A {firmware} feature activating a {layer} temporarily for the next keypress.
open source - Researchable, reproducible and tweakable because of the published source code or files. E.g. a {PCB}, {plate}, {case} design.
opening angle - 2 x {slant angle} in {split} keyboards. Alternative name: {split angle}.
operating force - The force measured at the {operating point}/{actuation point}.
operating point - The {travel distance} at the operation/actuation event.
optical switch - A {keyswitch} represented by very low or no input lag/{latency}.
optimization @ layout optimization
optimization model - Mathematical models to optimize the most effective arrangement of keys on a keyboard.
Oryx - A web based {QMK} configurator for some keyboard models by ZSA Technology Labs.
ortho @ ortholinear
ortholinear - The arrangement of keys into a regular grid, without horizontal or columnar {staggering}. See: {Planck}, {Preonic}
OS - Operating System
OSA - A {sculpted} {spherical} {doubleshot} {PBT} {keycap profile} with {homing dot}.
OSL @ one shot layer
OSM @ one shot modifier
otaku - A {keycap} set for {touch-typer}s ("geek" in Japanese). Artistic sets or {blank}s with no indication of the actual typed characters.
Outemu - A {switch} manufacturer and brand.
overlubed - Excess {lube} or improper {lubing} affecting sound, feel and function of a {switch}.
pad - A portion of the exposed copper/metal for soldering on a {PCB}.
panda @ pandaverse
pandaverse - The obscure world of {switch}es of the {Holy Panda} family as dubbed by ThereminGoat (review).
pangram - A short, sometimes surreal sentence that contains all the characters in a given alphabet.
paracord - A popular cable {sleeving}.
parasitic osctillation - An issue also known as {ringing}, e.g with {backliting}. Can cause the transistor to dissipate excessive power and heat the device up. A low ohm resistor will solve this issue.
PBT - PolyButylene Terephthalate. A durable, corrosion and UV-resistant {keycap} material. See also: {ABS}.
PCB - Printed Circuit Board.
PCB footprint - The standardized dimensions of electronic components.
PCB mounted (switch) - A {keyswitch} with 3 plastic legs, used fixed on the {PCB} (in contrast to {plate mounted} switches).
PCB mounted (stabilizer) - A {stabilizer} attached to the keyboard {PCB} as opposed to {plate mounted} {stab}s. Can be clamped onto the PCB or there are {screw-in} stabilizers.
PCB trace - The conductive copper paths of a {PCB}.
penalty table - A basic evaluation concept used for {logical layout design}.
PF key - A 'program function' key, mostly on vintage boards. Predecessor of {F-key}s.
PG @ NP
physical layout - The physical arrangement of the keys. Similar to {form factor}. (uni)
pin - Can be a reference to {controller} {I/O pin}s or the two metal contacts on the bottom of a {keyswitch}.
ping @ spring ping
pinout - The map of {I/O pin}s of a {microcontroller} or {development board}.
pixel - Reference to an individual {LED}.
PJRC - Designer and manufacturer of the {Teensy} {development boards} (web}.
Planck - A 12x4 {ortholinear} keyboard (without number row). See also: {Preonic}
plate - Usually the layer one puts the switches in, but there is also the {bottom plate}. Cut from different metals, {acrylic}, {FR4}, or 3D printed.
plate builder - The Swillkb plate & case builder is an online tool generating {plate} and {case} {DXF} files from {KLE} {raw data}. Available at builder.swillkb.com.
plate generator - The ai03 plate generator is an online tool generating {plate} {DXF} files from {KLE} {raw data}. Available at kbplate.ai03.com.
plate mounted (switch) - Switches intended to be used fixed onto the plate (in contrast to {PCB mounted} switches) have only the middle plastic leg on their bottom.
plate mounted (stabilizer) - A {stabilizer} attached to the {plate}.
plateless - A keyboard with {PCB mounted} switches, without a {plate}.
Plover - A free, open source {steno} program that lets you use your keyboard as a {steno machine}.
pole - The {housing pole} or the {center pole}.
poll rate @ polling rate
polling rate - The frequency of an {USB} device reporting its state, e.g. the keyboard {matrix}.
Pololu - A family of {development board}s based on the {Atmega32U4} {microcontroller}.
Pololu A-star - A family of {development boards} and a {bootloader} for {Atmega32U4} based boards like e.g. the {Pro Micro}. Based on {Caterina}, {open source} (git).
Polyoxymethylene @ POM
POM - Polyoxymethylene. A very smooth {switch} {housing}, {stem} and {keycap} material with relatively low melting point.
population size - A parameter of an {evolutional model}. The number of concurrent {layouts} per {generation} competing for survival.
poron - A polyurethane {gasket} material used in {gasket mount} {case}s.
positive slope - The keyboard's top plane is facing the user (in contrast to {negative slope}, where the {legend}s are facing away from the user).
prebuilt - A functional keyboard out of the box, as opposed to a {kit}, parts you need to assemble or building from scratch.
pre-travel - The distance prior to the {actuation point}.
Preonic - A 12x5 {ortholinear} keyboard (with number row). See also: {Planck}
printed circuit board - A {PCB} allows signals and power to be routed between electronic components without wires, as opposed to {handwiring}.
PRK - A keyboard {firmware} by @hasumikin with the {RP2040} as its target chip (github). Alternative to {KMK}.
Pro Micro - A popular and cheap {AVR} {development board} with {Atmega32U4} {microcontroller}.
profile @ keycap profile
progressive spring - A {spring} progressively increasing its force as the {switch} is pressed down.
pronation @ forearm pronation
Proton C - A {Pro Micro} alternative with an USB-C connector.
prototopre - Capacitive {foam and foil} {switch} combined with a dome (instead of a {spring}) (see {Topre} and {rubberdome}).
proxy - A local vendor/distribution partner managing pre-orders and shipping the products of a {group buy}.
PS/2 - A pre-USB connector type. See also: {DIN}, {USB}.
pudding keycaps - A {keycap} design with differently colored top part.
pull request - A request to submit code to {QMK} (or any other project on {GitHub}).
pulse wave modulation - A technique used e.g. for {backlight} dimming.
PWM @ pulse wave modulation
QC - Quality check.
QMK - Quantum Mechanical Keyboard. A popular keyboard {firmware} and its ecosystem (gmk.fm).
QMK Configurator - An online tool to configure the {QMK} {firmware} and {flash} compatible keyboards.
QMK Toolbox - A desktop tool to {flash} compatible keyboards with the {QMK} {firmware}.
QWERTY - The family of standard {logical layout} (with countless national variants).
QWERTZ - Multiple variations of {QWERTY} (with Z and Y swapped) used in Germany and many Central European countries.
r/MechanicalKeyboards - The biggest keyboard community on reddit: link.
r/MechMarket - A reddit sub for selling and buying keyboard related stuff.
r/mk - r/MechanicalKeyboards
r/mm - r/MechMarket
R2 - Round 2 or second run/{re-run} of production or row 2 of a {keyset}/{keycap profile} (important for {sculpted} sets).
R3 - Row 3. The shape of a {sculpted} profile's keys on the {home row}. See: {all-R3}.
rabbit hole - A reference to the (deepness of the) keyboard hobby.
raffle @ raffle sale
raffle sale - A mechanism to sell limited products to people who win the right of buying by chance.
rail - The features on either side of the {stem} guiding it during its movement. As well as the matching rails in the {bottom housing}.
random shit - Props on a keyboard photo.
rattle - The unwanted noise of the {stabilizer}, i.e. of {keycap}s larger than or equal to {2u}.
raw data @ KLE raw data
re-roll - A second turn of a {raffle} to distribute unpaid products.
re-run - A second/next production run of a limited product. See: {group buy}.
recolor - The same {switch} with differently colored {housing} or {stem}.
red @ red switch
red switch - A {linear} {switch}. Red was the {stem} color of light linears in the original {Cherry MX} lineup.
relegendable - A {keycap} with a transparent top part to put a piece of paper with custom {legend} below it.
repetitive strain disorder (RSD) - A group of keyboard related health issues.
repetitive strain injury (RSI) - A group of keyboard related health issues.
replacement span - The look-ahead perception of a typist. The number of characters you remember without looking at the text you are transcribing. The point at which typists relinquish further monitoring of the source text. (source).
rerun @ re-run
reset point - The {travel distance} where the state of a switch is reset to off (related: {hysteresis}).
retrobright - Mitigating the yellowing of an old plastic part (e.g. {case} or {keycap}), usually by UV light or chemicals like {hydrogen peroxide} (more).
retrobrite @ retrobright
retooled - A {keycap} or {switch} cast with new {mold}s.
rev - revision, e.g. Random Model Rev 3
reverse dyesub - A {dye sublimation} method: lighter {legend} on darker {keycap} achieved by dying the whole surface except the legend.
RGB - An {LED} with adjustable color (hinting at the color components Red, Green, Blue).
RGB lighting - A lighting feature of {QMK}.
RGB matrix - A lighting feature of {QMK}.
ringing @ parasitic oscillation
RGBW - An {LED} with a white (W) component in addition to the {RGB} colors (for more natural white light).
rollover - The term for pressing a key while a another key is already held down. Variants include {2KRO}, {6KRO}, and {NKRO}.
rotary encoder - An electronic component used to set the volume, brightness, scrolling etc.
row jump - While typing, skipping a row (also {hurdle}). E.g. typing MU on a standard {QWERTY} keyboard. A slow key combination {logical layout design} aims to minimize.
RP2040 - A cheap and powerful {microcontroller} chip by Raspberry. Featured on {Pi Pico}, {KB2040}, etc. {development boards}. For firmware see: {KMK}, {PRK}.
RSD @ repetitive strain disorder
RSI @ repetitive strain injury
RST - reset (marking on some {PCB}s or {development board}s)
Rub out - Equivalent to Backspace on some early keyboards like the {Knight keyboard}.
rubberdome - The classic, cheap keyboard without individual switches. Considered inferior to mechanical keyboards by some people, which of course is a more complex question.
runner @ GB runner
SA - A very high, {sculpted}, {spherical} {keycap} profile by {Signature Plastics}.
sandwich (caseless) design - A {case} built from {plate}s encompassing the {PCB} or the {handwired} circuitry, without outside walls. Used mostly in {low profile} DIY keyboards.
sandwich mount - A {mounting style} securing the {PCB}/{plate} between the bottom and upper {case} housing/frame. Screws go all the way through.
scan code @ scancode
scan rate - The frequency of updating the keyboard {matrix}. scan-rate-estimator
scancode - An identifier of a keypress used by the {firmware}, {keymap}s or by the {OS}. (See USB HID Usage Tables or QMK keycodes.)
schematic - The circuit diagram or logical map of a {PCB} using agreed symbols to describe electronic components and their connections.
scoop @ deep dish
scratchy - Inconsistent feel with changes in force or jumps in the stroke due to poor manufacturing or {lubing}. Opposite of {smooth}.
scratchiness - A property of a {keyswitch}. Depends on the material and surface of the {stem}/{housing}. See: {lubing}.
screw-in (stabilizer) - A {stabilizer} attached to the {PCB} by screws for better stability.
sculpted (keycap profile) - A {keycap} profile with differently shaped {cap}s in different rows. (As opposed to {uniform} keycaps.)
secondary legends - The {legend} on a keycap indicating characters/function of a secondary logical layer. Generally, characters typed by using a {modifier} like Shift/Alt/AltGr.
serial - One way of wiring to connect the halves of a {split} keyboard (doc).
ship of Theseus - A thought experiment: whether an object that has had all of its components replaced remains fundamentally the same object. Apply this to custom keyboards.
ShiroMicro - A {controller} type. A {Pro Micro} clone with {mid-mount} USB C connector by /u/elfmimi.
Sholes, Christopher Latham (1819-1890) - An inventor who patented the original {QWERTY} layout (among many other layouts) and designed one of the first commercially successful mechanical typewriters.
Sholes and Glidden typewriter - An early, piano-like typewriter designed by {Sholes, Christofer Latham} from 1874 which overtake in the market from the {Hansen Writing Ball}.
short - A mostly accidental path in a {circuit}. Generally, it's a problem, but can be also intentional ({hard reset}).
shorting - To connect two wires/electronic components and closing the {circuit}.
Signature Plastics - A {keycap} manufacturer known from its {SA} keycaps.
silent stem - Rubber pads on the {rail}s to dampen the sound of the {stem} when hitting the {housing}.
silicone grease - A material for {lubing} switches.
silk screen - The (usually white) layer on top of the {soldermask} on a {PCB} for adding labels, markings or artwork.
SK6812 - An addressable {LED} with voltage-independent color and brightness over a wide voltage range. LED quality is said to be better than {WS2812}.
SK6812 mini - Mini version of the {SK6812} with 3.5mm*3.5mm {LED} size. No other difference.
slant angle - Half of the {opening angle} in {split} boards.
slave - The separate {split} half without direct connection to the PC (contrary to the {master}).
sleeving - An external layer of cables to provide protection, increased stability or for aesthetics. Made of fabric or plastic mash. See: {Techflex}, {MDPC-X}.
slope - The forward-backward facing of the keyboard. A {positive slope} and {negative slope} is the facing forwards and backwards, respectively.
slope angle - The angle of forward-backward facing of the keyboard.
SMD - Surface mounted electronic components and {soldering} method.
smooth - Consistent linear feel with no changes in force or jumps in the stroke due to poor {lubing}. Opposite of {scratchy}.
Sn60Pb40 - A solder material with 60% tin and 40% lead ({60/40}).
socket - A device which makes temporary fixing of electronic components (e.g. a {switch} or {controller}) possible. See also: {hotswap}.
socketing - A temporary fixing of an electronic component (e.g. {microcontroller}, {keyswitch}). See also: {hotswap}.
soft reset - Software reset of the keyboard, usually with a key combination. (As opposed to hard reset.)
solder mask - A protective layer on top of the {copper} foil in a {PCB}. This layer gives the PCB its color (green, black, white etc.).
solder wire - The material you melt to solder. Comes in various thickness and compounds.
soldering - The method to semi-permanently fix electronic components with the help of a {soldering iron} and {solder wire}.
soldering iron - A tool for {soldering}.
soldering station - A tool for {soldering}.
soldering temperature - This one varies depending on the exact solder material or the component thickness, but 330-350°C is a good
sound dampening - Coping with the sound of hollow {case}s. E.g. with {foam} or silicone.
south-facing - E.g. a {switch} with {LED} holes in the front part of the bottom.
SouthPaw - A community member and a {form factor} with the {numpad} on the left.
SP @ Signature Plastics
space FN - Turning Space into a modifier (on a standard keyboard) to access another logical layer.
space-cadet - The {Symbolics space-cadet} keyboard designed by Tom Knight or a {keyset} with similar colorway.
space-cadet shift - Parentheses on Shift keys when tapped.
speed switch - A {keyswitch} with small {travel distance} to actuation. E.g. Kailh speed switches.
spherical - A {keycap} profile with a spherical well on the top (contrary to a {cylindrical} one).
split - A keyboard with two angled halves. Either separated or in one piece ({fixed-angle}).
split angle - The full {opening angle} of the halves of a {split} keyboard ({slant angle} x 2).
split Space - A Space key in two pieces for both thumbs.
spray lubing - No. Don't do this. If you are lazy, check {bag-lubing} instead.
spring - Part of a {keyswitch} sitting on the {housing pole}, controlling the {stem}'s vertical motion and partially defining the switch {weight}.
spring ping - The (often unwanted) sound a {spring} makes during the keypress. See: {lubing} or {spring swap}.
spring swap - To {mod} the {switch} by replacing the {spring} for altered {weight} or to mitigate {ping}.
springless - A {switch} without a {spring}, e.g. a {Hall effect} one.
sprue @ keycap sprue
stab @ stabilizer
stabilizer - A device with a metal rod to stabilize larger keys (equal to or over {2u}). (uni)
stabilizer bar - The metal part of the {stabilizer}.
stabilizer wire @ stabilizer bar
staggering - The physical arrangement of keys in horizontally shifted rows, vertically shifted columns or in an {ortholinear} grid.
standard bottom row - {1.25u} {modifier}s and {6.25u} spacebar.
standard keyboard - The 104/105 key {fullsize} {ANSI}/{ISO}/{JIS} keyboard generally with {QWERTY} or its regional variant.
stem - The moving inner part of a {keyswitch}, sitting on the {spring}. Stem color often indicates {switch type}.
stem hole - The cutout in the {upper housing} for the {stem}.
stem wobble - Movement (often unwanted) of the {stem} in N/S or E/W direction. More noticeable on higher {keycap} profiles, e.g. {SA}.
steno @ stenography
steno machine @ stenotype machine
stenotype machine - A special keyboard for practitioners of {stenography}.
stenograph @ stenotype machine
stenography - A writing method mostly used by court reporters. Words are {chord}ed ({strokes}) with shortcuts, allowing typing speeds in the 200-300 {WPM} range (without the strain of standard typing). (See: openstenoproject.org)
stepped keys - A {keycap} shape to avoid accidental hitting of Caps Lock and other {1u}+ keys (especially before {stabilizer}s became common).
sticker bomb - Covering the surface of the {case} with stickers to the point where the original surface is no longer visible (for aesthetics).
stroke - Firing a {chord} in {stenography}.
sublegend - Legends of the {secondary layer} on the {keycap}.
Super - A {modifier} introduced on the {space-cadet} keyboard. Sometimes an alternative name for the {GUI key} (Windows/Command).
supination @ forearm supination
surface mounted (SMD) - A soldering method better fit for automated manufacturing, where the components are soldered on pads (contrary to {THM} soldering).
SVG - A vector file format for {laser cutting} {plate}s and {case}s. Similar to {DXF}.
switch - A keyswitch is the basic electronic component residing below the keycaps.
switch filming @ filming
switch opener - A tool to take apart the switch housing e.g. to access the spring or the stem for lubing. Can aggravate housing wobble.
switch puller - A tool to remove keyswitches, e.g. from a {PCB} or {plate}.
switch tester - A tool to test and store different {switch}es. Usually, in the form of an acrylic plate.
switch type - Major groups of switches are {linear}, {tactile} and {clicky}.
switch weight - A parameter representing the force/weight needed to activate a {keyswitch}.
switching speed - A parameter of e.g. {diode}s representing the delay to change from ON to OFF state when the polarity changes. Depends on the junction charging/discharging and semiconductor material and quality.
Symbolics space-cadet - A legendary keyboard designed by John L. Kulp in 1978. Known for its many layers and {modifier}s ({Hyper}, {Super}, {Meta}). (wiki)
tactile - A non-{linear} {keyswitch}. Often used as a shorthand for silent tactiles. Another tactile with an audible click is a {clicky}.
tactile bump - The inconsistency in the {stem}'s linearity to give feedback for typers. Overcoming this bump requires more force, thus, the {tactile force} of {tactiles} is often higher than their {actuation force}.
tactile force - The keypress force measured at the {tactile point}.
tactile point - The keypress distance where you experience the {tactile bump} (or {click}).
tactile switch - A {keyswitch} with a {tactile} feedback (usually only switches without a clicking mechanism).
Tai-Hao - A Taiwanese manufacturer of various {keycap}s. Also a {keycap profile} ({cubic}).
Tangerine - A {linear} {switch} with {POM} {stem} and {UHMWPE} {housing} manufactured by {JWK} (more).
tap - A short press and release of the key (in contrast to a {hold}).
tap dance - A powerful {QMK} feature developed by algernon. You can specify keys that behave differently based on the amount of times they have been tapped (docs).
tapping term - The time limit defining what's a {tap} and what's a {hold}. Its default value is 200ms in {QMK} (docs).
TEA - A {low profile} {keycap} profile by designed by u/adroom.
Techflex - A type and family of cable {sleeving} and their manufacturer.
Teensy - An {AVR} {development board} family by PJRC.
tenkeyless - A keyboard without the numeric pad.
tenting - A laterally inclined {split} keyboard design.
tertiary legends - The {legend} on a keycap indicating characters/functions of the tertial {logical layer}.
through hole @ through hole mounted
through hole mounted (THM) - A soldering method involving holes on the {PCB} and components with long legs (in contrast to {SMD}).
THM @ through hole mounted
thock - The low pitched sound of a keypress.
thread per inch - A parameter of a {string}.
thumb cluster - The area for {thumb key}s, especially on {split} {physical layout}s (e.g. {ErgoDox}, {Atreus}).
thumb fan - A {thumb cluster} arranged in an arch.
thumb key - A key pressed with the thumb. In contrast to the {standard keyboard} boards with a {thumb cluster} use thumbs for more than just the spacebar.
tilting - The lateral inclination of the {split} keyboard halves. Alleviating {forearm pronation}.
tilt angle - The angle of the {tilting} of the halves of a {split} keyboard.
TKL @ tenkeyless
TMK - A keyboard {firmware}. {QMK} is based on {TMK}.
Topre - A Japanese keyboard manufacturer and their capacitive {switch} type.
total travel @ total travel distance
total travel distance - The full distance of a keypress until the {stem} hits the {bottom housing}. See: {bottom out}.
trace - A path of copper on a {PCB}.
trading keyboard - A custom or application specific keyboard for trading, e.g. Reuters keyboards manufactured by devlin.co.uk.
Trash Panda - A regular {linear} {keyswitch}.
travel distance - The distance a key has to be pushed down to be registered. Some {low profile} and {speed switch}es have shorter travel distances.
tray mount - A {mounting style} securing the {PCB}/{plate} to the bottom {case} housing with {mounting post}s.
Tribosys - A family of {lube}s.
Tribosys 3203 - A {lube} generally used for {switch}es.
Tribosys 3204 - A {lube} generally used for {switch}es. Similar to {Krytox 204g0}.
trigram @ trigraph
trigraph - Three consecutive characters of a {corpus}. Trigraph frequency is an inportant element of an {evaluation algorithm} and {logical layout optimization} in general.
triple-shot - A {keycap}s {mold}ed with three different colors. One mold for the external shape and two more molds for the primary and {secondary legend} makes this manufacturing method slow and expensive.
TRS - A type of 3-wire cable to connect {split} halves with the {serial} method (doc).
TRRS - A type of 4-wire cable to connect {split} halves with {I2C} (doc).
Tsangan - A layout which includes HHKB, 7U spacebar, split right shift, split backspace. Named after the Geekhack mod who kept asking for compatible keysets.
top housing - Part of a {switch} protecting and guiding the {stem}. May be hit by the {keycap} during a keypress. See: {housing}.
top mount - A {mounting style} securing the {PCB}/{plate} to the upper frame of the {case}. One type of this with {O-ring}s is called {burger mount}.
top out - The {stem} hitting the upper {housing} when releasing the key. Sometimes with unwanted sound amplified by {housing wobble}.
touch typer - A typist typing without looking at the keyboard.
touch typing - The proper method of typing: without looking at the keyboard (as opposed to {hunt-and-peck} style).
typing speed - The speed of typing, usually expressed in {WPM}, i.e. {KPM}/5. However, dividing with standard 5-character words is used ambiguously (with or without added spaces).
u - key unit, like 7u spacebar, {2u} Shift or {all-1u} {ortho}.
uC - An abbreviation of {microcontroller}.
UHK - Ultimate Hacking Keyboard. A modular {split} with {horizontal staggering}.
UHMWPE - A {switch housing} material.
ulnar abduction @ ulnar deviation
ulnar deviation - The outwards bending of the wrist in the plane of the desk. Alleviated by {split}/{fixed-angle} keyboards.
underglow - The {LED} {backlight} on the keyboard. These LEDs usually shine away from the {PCB} towards the desk surface.
underlight @ underglow
uniform (keycap profile) - In a uniform profile {cap}s in different rows have the same shape (contrary to {sculpted} profiles). E.g. {DSA}, {XDA}, {KAM}.
Universal Serial Bus @ USB
upper housing @ top housing
USB - Universal Serial Bus is a standard developed to standardize the connection of computer peripherals, such as keyboards.
USB C - A newer {USB} {connector type}.
USB host - Your computer or the device your keyboard is plugged into.
USB micro - An older {USB} {connector type}.
USB standard - The commuication standard describing {keycodes} and behaviour of compliant keyboards (doc).
UV printing - A {legend} printing method. Lacquer applied to the {keycap} is treated with UV.
velocikey - A {firmware} feature that lets you control the speed of lighting effects with your {typing speed} (doc).
vertical staggering @ columnar staggering
VIA - A desktop configurator for {QMK} to change {keymap}s (caniusevia.com).
vomit - A mixture of {keycap}s from various {keyset}s on a board, or a similar random mix from e.g. a {grab bag}.
Wada, Eiiti (1931- ) - Designer of the {HHKB layout}.
weight @ switch weight
winglatch - A style of {leg}s on the {upper housing} used to attach it to the {bottom housing}.
winkeyless - A layout similar to the invader layout, with a gap between Ctrl and Alt.
wire - The essential part for {handwiring}. Also, {stabilizer wire}.
wire balancing - Straightening/balancing the {stabilizer} wire to eliminate {rattle}. An unbalanced {stab} may otherwise cause rattle on one side of the spacebar.
wirewrap - An old technique somewhere between {handwiring} and {PCB}s, wrapping wire around posts without {soldering}.
WKL @ winkeyless
WKL blocker - Generally a 0.75u wide block on a {winkeyless} case at the positions between Ctrl and Alt.
WoB - White {label} on black {keycap}. A popular color combination.
wobble - Unwanted movement of the {keycap}/{stem} or the {housing}. The {housing wobble} may be mitigated by {filming}.
word boundary error - Multi-{stroke} conflicts in {stenography}. Some words are typed with more {stroke}s and {Plover} can't tell if it has to put a space or continue with the word.
Workman - An {alternative layout}.
WPM - Words Per Minute. 'Word' is usually 5 chars, sometimes 6 (because of the inconsistent handling of spaces).
WPH - Words Per Hour. See: {WPM}.
wrist extension - Bending your hand backwards at the wrist, towards the posterior side of the forearm. Sustained wrist extension can cause healt issues.
wrist flexion - Bending your hand down at the wrist, so that your palm faces in toward your arm. Opposite: {wrist extension}
wrist rest - A support for your wrist to mitigate {wrist extension}.
WRMDs @ WRMSDs
WRMSDs - Work related musculoskeletal disorders. A group of the many keyboard related health issues.
WS2812 - A type of addressable {LED}s commonly used in keyboard projects.
WS2812B - Same as {WS2812} but with reverse connection protection.
WS2813 - An {LED} or addressable LED strip similar to {WS2812} and {WS2812B} but with two data signal wires. Failure of an LED won't affect signal transfer unless two consecutive LEDs are broken.
XDA - A {uniform}, {spherical} {keycap} profile. Similar to {DSA}, but slightly higher with sharper edges.
YC8 - A type of detachable {aviator connector}.
ZMK - A keyboard {firmware} with wireless keyboards in focus: zmkfirmware.dev