WordLiteral = Identifier | '"' { CharacterLiteral } '"'.
Each word symbol corresponds to a character string and is written as a sequence of character
literals enclosed in double quotes. The character literals appearing in word symbols are the
same as those appearing in character symbols. For example:
It should be noted that
The double quotes enclosing a word symbol may be omitted, provided that the symbol satisfies the two following restrictions.
The word symbol may contain only the following characters: capital letters, small letters, digits, and underscores.
The first character of the word symbol must be either a capital letter or an underscore.
For example, here are two representations of the same word symbol: