On Monday, January 1, 2018 at 11:59:46 AM UTC-5, sawdustmaker wrote:
After all my years of woodworking you'd think I'd know this but thought I'd
ask.
Do (horizontal) rails ever extend over the top/bottoms of the (vertical)
stiles? I always thought rails stopped at the stiles but ....

Traditionally the rails are captured between the stiles, but I suppose you could have the stiles captured by the rails. My only thought would be that in the latter case you *might* risk binding of a solid wood panel when/if the stiles and panel both expand due to humidity. If the stiles capture the rails you eliminate any effect from the stile expansion.