When at least one file in the program is an ASCII-encoded file, the alphabet-name clause of the SPECIAL-NAMES paragraph must be specified; the alphabet-name must be associated with STANDARD-1 or STANDARD-2 (for ASCII or ISCII collating sequence or CODE SET, respectively).

When alphanumeric comparisons within the object program are to use the ASCII collating sequence, the PROGRAM COLLATING SEQUENCE clause of the OBJECT-COMPUTER paragraph must be specified; the alphabet-name used must also be specified as an alphabet-name in the SPECIAL-NAMES paragraph, and associated with STANDARD-1. For example:

Object-computer.  IBM-system
    Program collating sequence is ASCII-sequence.
Special-names.  Alphabet ASCII-sequence is standard-1.

When both clauses are specified, the ASCII collating sequence is used in this program to determine the truth value of the following alphanumeric comparisons:

  • Those explicitly specified in relation conditions
  • Those explicitly specified in condition-name conditions
  • Any alphanumeric sort or merge keys (unless the COLLATING SEQUENCE phrase is specified in the MERGE or SORT statement).

When the PROGRAM COLLATING SEQUENCE clause is omitted, the EBCDIC collating sequence is used for such comparisons.

The PROGRAM COLLATING SEQUENCE clause, in conjunction with the alphabet-name clause, can be used to specify EBCDIC alphanumeric comparisons for an ASCII-encoded tape file or ASCII alphanumeric comparisons for an EBCDIC-encoded tape file.

The literal option of the alphabet-name clause can be used to process internal data in a collating sequence other than NATIVE or STANDARD-1.