Hi ralphie,
Most of the abbreviations used by members of the forum can be found
here. In answer to your question (taken from that post);
Outright Player Win (OPW): The contestant deals for the highest (or joint highest) of the six offers, which is greater than their box amount OR the contestant no-deals to the end and wins an amount greater than any of the offers. (In theory a player no-dealing to the end and winning less than the lowest offer could also be credited with an OPL, but the first, and rarer, definition is the one for which it tends to be used.)
Proveout offer: An offer the banker makes after the player has dealt. The offer should be what the banker would’ve offered if the player had still been playing, but there have been times when the validity of proveout offers is doubted and they are normally higher than they would be in-play, to make the player feel guilty for dealing.