I’m using a tclproc tpsHL7CompareField that I’ve seen mentioned many times in this forum. In this case, I want to kill a message if a particular field is unvalued. The command I’m using is “tpsHL7CompareField {SEGMENT PID} {FIELD 3} {COMP 1} {LIST { }} {DISP KILL}” with many variations on the LIST variable where I want to indicate the field as unvalued. I’m hoping someone familiar with this proc can tell me how to specify “unvalued”. Seems like it should be so simple…and I’m sure it is for someone who uses tcl more than once a year. Thanks in advance!