It's the order in which the waveforms were defined - although this might depend on the version you're using (and if IC5141 whether you are using AWD or wavescan) - it rather helps if you say.
I can do:
and I get:
((1 3 4 5 6)
("/CLK" "HOLD_TEST" "/INM" "/INP" "/OUTM")
(I've already deleted waveform 2)
If I want to delete HOLD_TEST, I do:
The numbers in the first list correspond to the second list names. I did this in IC615.
Hope that helps,