[evince] A question about printers

["Ronald F. Guilmette" <rfg tristatelogic com>]

Greetings,

I have a question.  It is not really about evince, per se, but I think
that you folks may perhaps be able to tell me that answer, and that
would be quite helpful.

I'm trying to set up a fresh new FreeBSD 12.0-RELEASE system and the
support for my specific printer (Brother MFC-7860DW) is either broken
or non-existant on this OS.  That's unfortunate, especially given that
this same networked printer is, and was, supported right out of the box
on my old Ubuntu Linux 16.04 system.

At the moment, I'm just trying to figure out what the mechanism is by
which various applications, e.g. Evince, Firefox, etc. normally determine
the set of printers that are present and available, i.e. the ones that
are then offered to the user as alternatives in the print menu when a
print operation is requested.

How does Evince become aware of the set of available printers and their
names?  Is there a specific file someplace in the filesystem that holds
this list?  Or is there some specific API by which it is obtained by the
applications that need it, e.g. Evince, Firefox, etc. ?