DEC alphabet
From Computer History Wiki
DEC Alphabet is the name given to the cut-down alphabet used by to number things such as the contact fingers on the edge of standard DEC cards (the first use). It runs:
A,B,C,D,E,F,H,J,K,L,M,N,P,R,S,T,U,V
I.e. leaving out 'G', 'I', 'O' and 'Q', which when poorly printed might be mistaken for '0', '1', etc.
It stops at 'V' because FLIP CHIPs, and later boards in that system, only had 18 contact pads on the edge fingers. With the later Berg connectors, which had 40 pins, it was extended to use 'W'-'Z' as well.
