Custom Report for adults with no envelope number

[prentz]

This may already be posted somewhere and I just missed it. If so, I'm sorry.

I've been trying to run a custom report for adults with no envelope number. The results being returned include some adults who actually have an envelope number, but not all of them. What am I missing? I am going into personal profiles and the information entered in is:
Adult exactly matches "Y" and
Envelope number is less than 1 and
Mailing Category begins with Attender or
Mailing Category begins with Prospect

Any information would be appreciated. I'm sure it is something so easy I am overlooking it, but I can't find my error.

Thank you.

[Zorak]

You will need to wrap those last two conditions in brackets. You will see the bracket button on the screen where you edit record filter.