Is this the logo of an organization which deals with patents? Or does it represent something else?
At the inception of this site, I believe it was simply a way to draw attention to a certain type of question which was the primary focus of this site. I don't recall the symbol having any particular "meaning" in itself.
Featuring that tag seems largely irrelevant now since the site no longer has any specific mission statement in that regard, but there is no organization or government entity sponsoring that tag or behind this site.