2.3. Identifiers

Identifiers are used as names and also as reserved words.

    identifier ::=
       letter {[underline] letter_or_digit} 

    letter_or_digit ::= letter | digit 

    letter ::= upper_case_letter | lower_case_letter 

All characters of an identifier are significant, including any underline character inserted between a letter or digit and an adjacent letter or digit. Identifiers differing only in the use of corresponding upper and lower case letters are considered as the same.

Examples:

    COUNT      X    get_symbol   Ethelyn   Marion 

    SNOBOL_4   X1   PageCount    STORE_NEXT_ITEM

Note:

No space is allowed within an identifier since a space is a separator. References: digit, lower case letter, name, reserved word, separator, space character, upper case letter.