Well, all I can tell you is that the page I posted the link for tells you what, in general, thefont is used for, too.
So, the spell book and trade skill's use "FRIZQT__.ttf (the main UI font - NPC names, player names, spell names, item names, buffs, quest log text, combat text, button text)". That's as far as I can get you.
I have all of the fonts in my UI changed to "Emblem", and I currently use ElvUI (which made it a giant p.i.t.a. to change fonts), but, I used the method outlined on Vranx's site. To give me a bit of an extra edge I also installed the SharedMedia addon from Curse.com. All I can say is "It works for me".
While you can see that
everything is changed to Emblem, I'm sure something has been missed (but I haven't found it yet).
BUT, I figure you should just go with Phanx's way, because it's probably for the best.