Macs come with a print server installed by default. This means you don't need to install any drivers or software to print to the BYU campus printers. It's really easy to configure the campus printers natively to print from your Mac.
First open the Terminal, then type: cupsctl WebInterface=Yes and press enter. this enables the "admin panel" we'll use.
Open a browser to: http://127.0.0.1:631/admin. Click Add Printer. You may have to authenticate: type your Mac user name and password (the one you login with when you start it up).
Of all the options that appear, choose "LPD/LPR Host or Printer." Then Continue.
For black & white printers, put: lpd://MYBYUID@isis.byu.edu/CampusBW in the textbox. Or for color, put: lpd://MYBYUID@isis.byu.edu/CampusColor -- Then make sure to replace "MYBYUID" with your myBYU username (formerly "Route-Y" username). Then Continue.
Type a name, description, and location of your choice. I usually call it "CampusBW" (no spaces allowed in the name) -- and the description is similar since that's the text that appears in the list of printers on my Mac. Then Continue.
In the list, choose "Generic" -- then Continue.
In the next list, I usually choose "Generic PostScript Printer (en)" or the option most similar to it, since this varies a little. Then Add Printer.
You're done! When you go to print something, choose the campus printer, then swipe your ID card at any of the Pharos printing stations in buildings around campus.
https://island.byu.edu/linux/content/how-use-campus-pharos-printing-under-linux (I updated the instructions and added my own notes, as these are a bit dated.)