DEC alphabet
From Computer History Wiki
DEC Alphabet is the name given to the cut-down alphabet used by DEC to number things such as the contact fingers on the edge of standard DEC cards. 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.
