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2.3 Identifiers and keywords

Identifiers (also referred to as names) are described by the following lexical definitions:

  identifier | ::= | (letter|"_") (letter | digit | "_")*
  letter | ::= | lowercase | uppercase
  lowercase | ::= | "a"..."z"
  uppercase | ::= | "A"..."Z"
  digit | ::= | "0"..."9"

  Download entire grammar as text.

Identifiers are unlimited in length. Case is significant.