Tables with different pop or household counts. "Population for whom poverty status is determined"

Hi,

Some tables use a lower (and perhaps higher??) number as a starting point such as S1701. This is usually stated in the field titles somewhere (which is great! ). Some tables have a population number that matches what I expect (on most tables). Sometimes it is different, I think due to people not wanting to disclose this info (they skip the question). However, I don't think they always state it in the table and sometimes the numbers are different. Some tables just have field elements as a percent etc. and I can't know what the starting point was. Did they use the full sample size or not? Is there any reference or method to know which tables use the full sample or not? A few percentage points diff is OK, but what if its 10% or higher, I've seen 15%?

Any advice or thoughts.

Thanks

Tom