>>This thing is still very hard to understand for me. I think the easiest here would be
>>
>>and Client.ModDate >=@MinDateOf3Dates OR Client.NoStatus NOT IN (@Status1, @Status2, @Status3)
>
>Yes, it the date would always be the same value. But, that was just an example.

I think you should try to express the logic as simple as possible in order to easily understand months from last time you looked at.

Say, if I see

status = @Status or status = @AnotherStatus or status = @ThirdStatus

I always suggest a re-write into this form

status in (@Status1, @Status2, @Status3)

which is much shorter and easier to understand especially when combined with other conditions.

So, my suggestion would be to simplify as much as possible.