Mould numbering refers to alphanumeric codes embossed into the shells of keyboard switches when they are moulded. In Tai-Hao practice, with a number such as "A10", "A" indicates the mould, and "10" indicates the cavity within the mould. The purpose of the numbers is to indicate which mould and cavity has failed when manufacturing defects occur.
With Alps SKCL/SKCM series switches, there is a possibility that the circled numbers indicate the batch or shift, while the top-right code indicates the mould and cavity.
The typeface, schema and position of mould numbering plays a useful part in identifying unbranded switches, particular Alps clones.
<mould number> ::= <number-part> <number-part> ::= <number> | <number> "," <number-part> <number> ::= <compass-point> ":" <char-part> <compass-point> ::= "N" | "NE" | "E" | "SE" | "S" | "SW" | "W" | "NW" <char-part> ::= <char> | <char> <char-part> <char> ::= "A" | "#"
- Letter (A-Z) placeholder
- Digit placeholder
- "SE:A###" covers "A1" to "Z999", positioned south east (towards the front of the switch, on the right)
A string of # symbols does not require a digit to be at each #: every digit place except the first is optional.
- String literals
- Rotated characters: http://imgur.com/a/hXBVa#2
Examples from various unbranded Alps clone switches
- Correspondence with Tai-Hao, 2016-11-01