Hi, all. I know this is basic, and I think I have done this before, but I haven't been successful this time. **In a Routing Rule,** I would like to take the value of MSH:9.2, see if that value does NOT exist in a lookup table, and ultimately return out of the rule if true. So, if my message is an "A05", but "A05" is not in a particular lookup table, then it evaluates to 1, and I execute my action of "Return" and the rule ceases processing. Is there something incorrect with my sample code below? ..DoesNotIntersectList(HL7.{MSH:9.2}, "ValidAdt.lut")  Thank you in advance for any insight! Bill