In SQL, wildcard characters can be used in LIKE expressions; the percent sign % matches zero or more characters, and underscore _ a single character. Transact-SQL also supports square brackets ([ and ]) to list sets and ranges of characters to match, a leading caret ^ negates the set and matches only a character not within the list. In Microsoft Access, the asterisk sign * matches zero or more characters, the question mark ? matches a single character, the number sign # matches a single digit (0-9), and square brackets can be used for sets or ranges of characters to match.