Displays whether or not identifier checking is enabled. You must enclose reserved words from the ANSI/ISO SQL standard within double quotation marks to supply them as identifiers in SQL statements. When you enable identifier checking, SQL issues an informational message after statements that misuse ANSI/ISO reserved words. For a list of the reserved words, see Oracle Rdb SQL Reference Manual. By default, identifier checking is disabled. To enable it, use the SET KEYWORD RULES statement.