It's American slang, Pete, generally used by a younger generation of teens and 20-something-ish folks. It is used in informal or popular cultural contexts, between friends, but would be wholly out of place--and would thus be inappropriate--in a professional environment or workplace.
I'm not quite sure how to translate it. I've never liked the phrase myself due to its sexist implications. I have heard my students of both genders use the phrase. Most often, the phrase is used as a metaphor to declare one's mastery or ownership of a given object. It could also mean something like, "here on UU, we disregard convention and make our own rules."
To me, the phrase is somewhat akin to wearing a t-shirt with the image of Che Guevara printed on it. The t-shirt is supposed to express the wearer's commitment to "radical" or "revolutionary" ideas, but leaves the entire system of capitalist production and consumption (which produced the t-shirt in the first place) unquestioned. Likewise, the phrase "here on UU we make appropriate our b---" portends to reject convention even as it confirms rather than questions the convention of chauvinism.
By the way, I know that Seeso was just playfully saying, in his role as a UU moderator, that on this forum it is fine to use any icon, whether or not it seems "appropriate."
but I don't know what this means? How will I use these contacts and how will they use my details? Why would anyone want to be friends with an opinionated old fart like me in the first place 
