The GnuCOBOL 3.1 RC-1 programmer's guide does not reference PIC 1 (as far as I can see by quick search of syntax of PICTURE-STRING).
AXXXXA.cbl: 146: error: invalid PICTURE character '1'
AXXXXA.cbl: 146: error: PICTURE string must contain at least one of the set A, N, X, Z, 1, 9 and *; or at least two of the set +, - and the currency symbol
Which is curious because the error message refers to 1 as a valid character in the picture clause.
1. How can I get this code to compile and run?
2. How could have I found that answer myself?