Musical terms
In some cases, an abbreviation from one language means something entirely different in another language. For example, "Tr." could refer to drums or trumpet. If the composer wasn't German, it definitely isn't the drums. A German composer wouldn't abbreviate trumpet as "Tr." because that's used strictly for drums. Similarly, "Kb." could refer to the double bass in German or the keyboard in English. And (for obvious reasons), "Fag." is only used in German and Italian music-- never English!
There are a few Italian words that are used across all languages of music notation, and these are the ones used for dynamics and tempo (e.g. "mezzo-forte" and "allegro"). But no musician would call those English words!
Aside from the standard Italian dynamics and tempos, the remainder of music notation is generally written in the composer's native tongue. I am looking at some examples right now; an American piece uses "in a strict tempo", "sizzling", "much brighter", and "mysterious". An Italian piece uses terms like "tranquillamente", "energico", and "sostenuto". A German piece has terms like "nicht schleppend", etc. These terms would never appear in music written in a different language.