The standard (default) character set used by High Level Assembler is a subset of the EBCDIC character set. This subset consists of letters of the alphabet, national characters, the underscore character, digits, and special characters. The complete set of characters that make up the standard assembler language character set is shown in Table 1.

+ - , = . * ( ) ' / & 

For a description of the binary and hexadecimal representations of the characters that make up the standard character set, see Standard character set code table.

When you code terms and expressions (see Terms, literals, and expressions) in assembler language statements, you can only use the set of characters described above. However, when you code remarks, comments, or character strings between paired apostrophes, you can use any character in the EBCDIC character set.

Whenever a lowercase letter (a through z) is used, the assembler considers it to be identical to the corresponding uppercase character (A through Z), except when it is used within a character string enclosed in apostrophes, or within the positional and keyword operands of macro instructions.

Compatibility with Earlier Assemblers: You can specify the COMPAT(MACROCASE) assembler option to instruct the assembler to maintain uppercase alphabetic character set compatibility with earlier assemblers for unquoted macro operands. The assembler converts lowercase alphabetic characters (a through z) in unquoted macro operands to uppercase alphabetic characters (A through Z).