Question about formatting a submission. I know from studying ancient history that when I use a Latin word I am required to have it in italics. But does the same apply to fiction? I currently reading a Roman HF that places Latin terms in italics, but others don't. So, in my first chapter I use the term mansio (a bit like a inn, but used only by people on imperial business) or should I italicise it to mansio?
Is there a rule about this, or just a house-style?
In this case, it's house style. I would do two things:
1. Be consistent; do it every time if you italicize or underline (some houses still request underlining, but you can change italics to underlining at submission).
2. Keep a list of every "special" word you use—so Latin words like mansio, place names, and the names of characters (even though you wouldn't italicize them), for instance. Your editor will bless you later because it avoids having mansio changed by a proofer to mansion, for instance, and if they decide to italicize just once, or never, or create a glossary or a map, etc. it makes their job much easier.