Illegal Re-entry?

[Mark Dexter]

Originally posted by DrC.
As we were told in our rules interpretations,

"You don't have to Play a Play"
"But you have to Sit a Play"

I like this saying. Has the first rule changed recently? I have an illustrated rules book (not the official one) which stated that the sub needed to play some length of time. On reading the rules, however, I see no such requirement.