I subscribed to a trading system, and I got an email recommending various trades. Can you explain what the terms mean?

You may get an email which says:

Sell to open 200 IBM @ stop 22.75 - Likely fill at 22.80 at 2:34 pm

This means: "Enter at your broker a trade to Sell Short IBM @ STOP 22.75." (If you do not know the terms "stop order" and "limit order," see related article Stops and Limits.) Notice that, when appropriate, Collective2 also tells you what price it expects you to have received, if you entered the order at the exact instant that the system vendor did. (This is what likely fill means).