11. Identifiers

• An identifier is a name that you invent and attach to a definition.

• Identifiers can be symbols representing variables, constants, procedure names, code labels, segment names, and user-defined data types such as structures, unions, records, and types defined with TYPEDEF.

• Identifiers longer than 247 characters generate an error.

• Certain restrictions limit the names you can use for identifiers. Follow these rules to define a name for an identifier:

  • The first character of the identifier can be an alphabetic character (A–Z) or any of these four characters: @ _ $ ?

  • The other characters in the identifier can be any of the characters listed above or a decimal digit (0–9).