Quark's bar takes payment in Latinum; and perhaps, as discussed in this question - in Federation "credits" (backed by something - not clear what). Now, in another discussion e.g. in this answer, the mechanism of distributing Latinum or credit is supposedly not interesting.
Except - it's very interesting. Let's By what mechanism does a Federation subject, or military personnel ("Starfleet"), get either credits or Latinum? Is there a wage? An allowance? Savings?
Or - maybe they don't get them at all? i.e. maybe Quark logs orders then bills the Starfleet directly? I don't remember DS9 scenes with Starfleet personnel paying or settling their tab.