[Dx4win] Paper QSL Filter

[n4ss at bellsouth.net]

I bet this one has been beat to death and I'm sure I'm missing something real simple.
Using Version 7.01. What fields are commonly used when entering a paper QSL that will distinguish it from a LOTW entry?  Is Upl Cnf a good one to use on a filter since it is only updated by an ADIF import from LOTW?
Many tnx,
Mack N4SS (Old ham trying to catch up with new stuff)