Yes it's documented in VFP help. See Filter Conditions for Queries and Views. It's also one of the standard SQL Operators.

>Wow. That's even shorter than Naomi's solution. I don't see anything about the IN in the VFP help. Is it documented anywhere?
>
>
>>

>>select maillist.* ;
>> from maillist ;
>> WHERE  personid IN (select personid from list_members where list_id > 67) ;
>> order by company
>>

>>