[CQ-Contest] "Z" in UBN Reports?

[btippett@alum.mit.edu (Bill Tippett)]

2003 CQ WW CW and SSB UBN reports available at:
http://cqww.com/

But does anyone know what this "Z" means?

1395  Z FP8AP(16)

I'm guessing it means an unverified call
which is deleted without penalty (except
for multiplier credit in this case).

73,  Bill  W4ZV