Can someone please point to documentation concerning the trust field (i.e. the field that says "+0 / =0 / -0" for new profiles") for Bitcointalk.org profiles? I've searched for documentation besides what you get just by clicking on the word "trust", but can't find anything.

How is the trust used? I get the impression people use this site as platform for buying/selling in addition to just posting questions and answers?

Thank you,
McMurdo