The most intriguing part of the keyword is or "c extra quality." In file-sharing and torrent communities, letter grades (A, B, C) combined with "extra quality" or "HQ" (High Quality) serve as release labels.
"Extra quality" in this context seems a bit ambiguous but could imply an expectation of exceptional performance, perhaps in a role or in meeting certain... conditions.
So, what does "extra quality" mean in the context of backroom casting? In essence, it refers to the perceived value or advantage that comes with securing a role or project through unofficial channels. For talent, this can mean getting a foot in the door, securing a coveted role, or gaining access to exclusive opportunities. For producers and casting directors, it can mean finding fresh talent, securing A-listers for a project, or getting ahead of the competition.