This week's book giveaway is in the OCPJP forum. We're giving away four copies of OCA/OCP Java SE 7 Programmer I & II Study Guide and have Kathy Sierra & Bert Bates on-line! See this thread for details.
I'm not sure which exact icon you are looking at, but if you go into a forum like "Java in General" where you have a list of all the thread titles, if you scroll to the bottom, most of the icons are described there.
Let us know if that helps, or if there is something missing. Or if I'm misunderstanding your question.
There are only two hard things in computer science: cache invalidation, naming things, and off-by-one errors