What in VFP 5 will be compatible with VFP 3?

If I create a form or class, or even a database container,
using VFP 5, will I be able to edit any of them in VFP 3?

I know you won't be able to execute a VFP 5 APP in VFP 3, and probably vice versa.

I ask because I develop in a WIN 95 environment but I have
clients how still use WIN 3.1.

Jody