TRAP - specify whether to terminate if a command fails.

$*$TRap $*$TRap ON: tells EXEC to terminate immediately if a system command fails or if EXEC finds some other error (e.g. a syntax error in an EXEC directive). This is the default when EXEC begins execution.
$*$TRap OFF: tells EXEC to keep on going if an error occurs. If a syntax error occurs in an EXEC directive, the whole directive is discarded.