If you want to do that, it might be best to exclude colour from the known-switch classification, because numerous switches changed colour for no reason (including Xiang Min KSB, Acer, Cherry MX Lock etc). Other switches changed colour for no
known reason, but we don't know that they aren't different in some way (e.g. kps's vintage Cherry MX "black" switches in weird pastel shades).
Travel could be something like:
Z, zero: touch screen
S, short: t < 2.5 mm (mostly scissor)
R, reduced: 2.5 < t < 3.5 mm
M, medium: 3.5 ≤ t ≤ 4.5 mm (Alps to BS)
E, extended: t > 4.5 mm
[wiki]Cherry ML[/wiki] is 3 mm, [wiki]Futaba low-profile linear[/wiki] is ~2.7, and [wiki]RAFI RS74M[/wiki] is 2.5. According to the wiki, "Because of the size of the scissor mechanism itself, scissor switches with key travel higher than 2 mm are uncommon."
Year of introduction is too hard to guess correctly and too subject to error, especially with Cherry MX (where our years are all messed up and missing), or simply impossible to discover; even getting the decade right could be tricky, but it would be an idea: 6-9 (1960s to 1990s), 0-5 (2000s to 2050s), after which we'd need something new (by which time, keyboards will probably be obsolete anyway, and probably human society along with it at the rate that the planet is self-destructing).
The objective characteristics that I would include would yield the following schema:
- "DSC": Deskthority Switch Catalogue
- " "
- Contact mechanism (L, M, C, H, E etc per unknown switches, but not U)
- Key weight (S (w ≤ 35 cn), M (35 < w ≤ 65 cn), F (65 < w ≤ 80 cn), H (80 < w ≤ 100 cn), U (100 cn ≤ w))
- Key feel (L linear, T tactile, P parabolic, F flat panel (touchscreen))
- Audible indication (C full-volume click, S soft click, U undamped (loud clacks expected but not guaranteed), Q quiet switch (touchscreen, scissor switch, damped mechanical etc — anything that makes low noise by design))
- Travel (Z, S, R, M, E per above)
- Decade (0–9)
- Disambiguation code (nn)
e.g.
Cherry MX Blue:
DSC LMTCM801: metal leaf, medium weight tactile click switch with medium travel, first one to be catalogued from the 1980s
Matias quiet:
DSC LMTQM101: metal leaf, medium weight tactile quiet switch with medium travel, first one to be catalogued from the 2010s
Typical scissor switches:
DSC MFTQS9__: membrane, firm, quiet switch with short travel, guessing they're a 1990s invention (you can't actually apply this schema to a switch
type, so 01 would be whichever specific product line we write about first, and I doubt anyone would).
Sound level is subjective, both perceptually and due to keyboard construction: my [wiki]Datacomp DFK-192[/wiki] has a gentle damped sound solely due to its construction, and is far quieter than typical Alps keyboards. Cherry MX Blue switches are almost inaudible without keycaps, so the keycap construction is largely responsible for the sound level. I would class Topre and most rubber domes as U (undamped) as you get a fair rattle off them: my boss jokingly accused my Topre Realforce as being a really loud keyboard, because compared to his scissor switch, the slider rattle makes a lot of noise.
Scissor rubber domes however are inherently quiet, as there is no keycap shaft to induce rattle and the parts are too small for the hard stops to be heard, so they're Q, as with Alps cream damped and Matias quiet, and touchscreens.
Other considerations include:
- Alternate action/latching: these can be linear or tactile
- LEDs, jumpers, diodes — relevant?
- Keycap mount — relevant? Maybe add this at the end as an optional letter after the decade and disambiguation digits, as it's not a fundamental switch characteristic (though in most cases it corresponds with or even requires a shell redesign, e.g. the shell change required for the Himake AK-CN2 to accommodate Cherry keycaps)
- Company code? Maybe for ease of recognition, disambiguation would have a company code, e.g. CH Cherry, AL Alps, FJ Fujitsu, IB IBM, FA Futaba ...
Cherry MX blue could be as long as:
DSC LMTCMNLDJMCH801 after adding N (normal switch), LDJ (LED, jumper and diodes available), M (Cherry MX mount), and CH (Cherry) to the code — this shows the down sides of adding too much detail.