When mystified, do a Google search for "Bike Forums [unknown acronym or word]". It will bring up a rash of references. Some will just have the acronym, but usually there will be others that also show the unabbreviated term.

Seeing the acronym in a different quotation also gives you a better shot at figuring out the meaning through context. Example: if you saw "Put the axle in the DO's and tighten the QR skewer," you'd probably understand both abbreviations.

Search engines haven't failed me yet. Google just happens to be my favorite.