Category names, category descriptions, entry names, and entry text do not accept localization keys (IE, they don't translate them). I assumed this would be a thing since I was able to use localization keys for both the landing_text and subtitle of my book. I like having all of my english in one place.

@Vazkii Oh, that's too bad. I should have mentioned another reason I wanted this — I'm probably going to make two separate guidebooks for my mod and change which one is used via a config (changing specific places to take out a "story" aspect that doesn't make sense for modpacks); I can reuse some of the english if this is a thing, but without it I have to clone most of the text.

Isn't this also like, way worse for translators, as well? Having to edit & pass around more files than just a single lang file?

I'm going to move this to "intended behaviour".