For HALT and NOMETHOD, a SYNTAX condition is raised with the appropriate Rexx error number.

For SYNTAX conditions, the clause in error is terminated, and a SYNTAX condition is propagated to each CALL instruction, INTERPRET instruction, message instruction, or clause with function or message invocations active at the time of the error, terminating each instruction if a SYNTAX trap is not active at the instruction level. If the SYNTAX condition is not trapped at any of the higher levels, processing stops, and a message (see Appendix C, Error Numbers and Messages) describing the nature of the event that occurred usually indicates the condition.

For all other conditions, the condition is ignored and its state remains OFF.