>Hi Charlie,
>
>There are a number of potential problems that come with using the FROM clause of DEFINE CLASS. We could probably start a wiki topic about this to localize the pros and cons, but off the top of my head here's why I never use the FROM clause of DEFINE CLASS
>
>1) Can't use the invocation stack for sensibly locating class definitions. (I do this a lot).
>
>2) Thereafter moving classes from one PRG to another breaks code. (I do this a lot).

The good side of this would be the documenting nature of the clause. In a vcx, you always have a link to the parent class; in a prg, there's none, unless you use the From clause.

Of course, some discipline would enable both: adding the link in a comment (so we don't have what you complain about), and if it's hard to maintain it once the parent class is moved to another prg, there should be a trail in the comment in the original prg ("class ParentRat moved to OldRats.prg").