(1) A character other than a digit, a letter, or one of these characters: $, #, @, ., or _. For example, the following characters are special characters: *, +, and %.
(2) In COBOL, a character that is neither numeric nor alphabetic.
(3) In REXX, a token that acts as a delimiter when found outside a literal string. Special characters include the comma (,), semicolon (;), colon (:), right parenthesis ()), left parenthesis ((), and the individual characters from the operators.
(4) A character that is not alphabetic, numeric, or blank. For example, a comma (,) or an asterisk (*).
(5) A non-alphabetic and non-numeric character, such as %, &, /, ?, ], and a number of other characters that have a unique function in the SQL language.