Mr. Hockey-
A Reverse bet is actually a short-hand for making two IF-bets. A Reverse bet on teams A and B produces two IF-bets:
1) If A wins, then also bet on B.
2) If B wins, then also bet on A.
Now, at the place where I wrote software, we had two types of IF bets: Single Action and Double Action.
Single Action: If A wins, then...
Double Action: If A wins or ties, then...
Some sites call the Single Action type: "IF Win-Only".
My guess would be that the WIN Reverse is like the Single action. The ACTION Reverse is probably the Double action case.
Check with the book to be sure, but you can use my description to pin them down on the explanation.