EQA1820E Invalid double byte alphanumeric character found in a COBOL DBCS name. Valid COBOL double byte alphanumeric characters are: A-Z, a-z, 0-9.

Explanation

Alphanumeric double-byte characters have a leading byte of X'42' in EBCDIC and X'82' in ASCII. The trailing byte is an alphanumeric character. The valid COBOL subset of these is A-Z, a-z, 0-9.