1961–1986 (year letter + month letter)
1961–1986First letter = year (A = 1961, B = 1962, …, Z = 1986). Second letter = month (A = January, B = February, …, L = December). Remaining 3-5 digits are a production rank. Example AB1234 = February 1961.
Gotchas & format-specific sources
- Distinct from the 1987–1996 format because the second character is a letter (A–L) rather than a digit.
- Matched before the 1987–1996 rule so the two-letter form wins over a letter+digit form when the second character could be either.