On Land

Environment Information
At Rill Architects we run ArchiCAD on macOS. If you work at Rill, this is your stuff. If you don't, but you work in ArchiCAD, you may find something interesting. Anybody else, I don't know.
All the server libraries are in a volume called "2 Libraries", whose icon is a carrot which predates OS X and looks it, and we call the libraries volume the carrot. This is what's there:

BIM Server Libraries. Copies of our standard libraries for use in Teamwork projects.

Library Container Files. An LCF is a compressed archive of a library. It loads very fast and can't be messed up, so it's good for taking projects on the road assuming you don't need to modify standard parts. I try to update the LCF of our current versions' library (13 and 16 at the moment) on a weekly basis. But I might forget, and I certainly modify objects throughout the week, so if you need the LCF you should make sure it's up to date.

Master LIB [n]. Where n is between 7 and 20. The Master folder contains the current "1 Rill LIB[n]" folder, which is standard library that must be loaded for all current projects. It also contains a "Development" folder, which should generally not be loaded; things in there are either broken, unfinished, or otherwise unworthy.

When we start using a new version of Archicad, I copy the entire Master LIB folder and give it the new number. When you switch a project to a new version, you should also change to the newer Master LIB. It will be virtually identical to begin with, but over time the old versions will fall behind. I generally only treat the newest Master LIB as "live" for the purposes of new development and bug-fixing. Back-saving objects, unlike PLN files, is nearly prohibitive in its awkwardness.

Other LIBs. Just what it says. Old project libraries from the pre-embedded days. Old Archicad libraries. (I've lost the 5.1, but we still have the 6.0.) Extracted versions of recent/current Archicad libraries. (Archicad libraries are LCF files. If you want to search them using the Finder, they need to be extracted.)