Poperb, no problem - all of us were new once! It's never a bad thing to ask.
If you look at the THR Library (link in the top right corner at the top of a thread or THR screen - scroll up to the top if you don't see it), you'll see a section called "Acronyms, Abbreviations, and Terms". Click in there, and you'll find a list of commonly used short-cuts that you'll often encounter here.
Hope this helps.