Erik,

>>That'd be neat if true, but very tough unless VFP went and refactored it not to used the INLIST function - you have to check each record against the function return. You'd also have to change VFP's refactoring if the INLIST() were used in combination with another function by something, or contained in another expression like an IIF()).
>>
>>IN with a list of values (eg: ZipCode IN ('06511','90210','66666')) or a subquery is definitely optimizable.
>
>I see where it might be difficult for VFP to pull off, unless, like you said, it internally just 'emulates' the function. I confirmed my statement though- its a valid optimizablwe relational operator.

It would be great, because in this case we don't need to rewrite our classes. I'll check.