Hello,
basically title.
I often found such icons in CSS snippets, but never truly understood where I could see them all and now that I’m trying to do stuff with icons for my style I would truly benefit understanding how to find all these icons and how I could properly use them.
Thanks in advance to anyone who will try to help me :D
It is. But note that that site shows code in mozilla-central repository, i.e. code for nightly which can change quite often.
You can switch to release repository by replacing the mozilla-central part of the url with
mozilla-release