What does besom, welt and quarter pockets mean?
Welt/quarter pockets vs. besom: welt or quarter pockets have been the traditional pockets on slacks for a very long time. They are designed to hold your hand inside the pocket because they are cut at an angle. Besom pockets are a fairly new tradition in pockets on slacks and suit hip pockets. They are typically slits where the material from both sides meet and closes without overlapping. They are meant to look less visible and more as a part of the overall silhouette. "Flap" pockets are on sport coats and suit jackets at the hip. They offer a "flap" over the pocket.

Should I dry-clean all wool products?
Yes, anything consisting of wool, should be dry cleaned only. Wool will shrink to an unbelievably small size and should never be laundered.