JB: Yes, they are threads that "Stick" at the top of the forum main page and never move down the page. A Sticky usually contains pertinent information that one can find easily each time you visit the forum. For instance on the Orchid Forum:
http://garden.org/forums/view/... there is a Sticky at the top that contains lots of links for information regarding orchid plants. I see there are two on the Houseplants Forum. Not all forums have Stickies but if there happens to be good information for one on any forum, I'm sure the forum moderator could be convinced to add a sticky.