Symbol length

High Level Assembler supports three types of symbols:

Ordinary symbols: The format of an ordinary symbol consists of an alphabetic character, followed by a maximum of 62 alphanumeric characters.
Variable symbols: The format of a variable symbol consists of an ampersand (&) followed by an alphabetic character, followed by a maximum of 61 alphanumeric characters.
Sequence symbols: The format of a sequence symbol consists of a period (.) followed by an alphabetic character, followed by a maximum of 61 alphanumeric characters.

External symbols are ordinary symbols used in the name field of START, CSECT, RSECT, COM, DXD, and ALIAS statements, and in the operand field of ENTRY, EXTRN, WXTRN, and ALIAS statements. Symbols used in V-type and Q-type address constants are restricted to 8 characters, unless the GOFF option is specified, which allows symbols up to 63 characters. You can specify an alias string of up to 64 characters to represent an external symbol.