OpenType fonts that include a name with name ID of 6 should include these two names with name ID 6, and characteristics as follows:
- Platform: 1 [Macintosh]; Platform-specific encoding: 0 [Roman]; Language: 0 [English].
- Platform: 3 [Windows]; Platform-specific encoding: 1 [Unicode]; Language: 0x409 [English (American)].
Names with name ID 6 other than the above two, if present, may be ignored.
When translated to ASCII, these two name strings must be identical and restricted to the printable ASCII subset, codes 33 through 126, except for the 10 characters: '[', ']', '(', ')', '{', '}', '<', '>', '/', '%'. Some implementations have a 63-character length limit; however, a 127-character length limit is recommended.
The term “PostScript Name” here means a string identical to the two identical name ID 6 strings described above. See https://docs.microsoft.com/en-us/typography/opentype/spec/recom
Professional font design software like Glyphs App and FontLab will do this for you automatically.