The ERROR statement modifies the behavior of the previous statement (which must exist) and is not a valid statement in its own right. KCML will indent the ERROR statement itself and subsequent statements until the start of the next line to make it plain that these statements form a group which will be skipped unless there is an error.

The error statement, if the error is not taken, performs a jump to the next program line. This can cause problems if line numbers are to be removed and it is recommended that the statement is replaced by the ERROR DO statement whenever possible.