When should Latinisms be Italicized? [duplicate]

Solution 1:

Obey the dictates of your manual of style, either the one you've chosen or the one thrust upon you. I use The Chicago Manual of Style, which specifies italics for Latin words that have not been adopted into the English:

His modus operandi is veni, vidi, vici.

I would say that any Latin term that has its own acronym in police procedures (i.e, "MO") has been incorporated into the language.

CMS places scholarly abbreviations ("ibid.", "op. cit", etc.) in roman type:

The abbreviation "op. cit." stands for opere citato, Latin for "in the work cited."

The word sic, Latin for thus, to leave no doubt that a quoted passage is how it actually appears in its source, is italicized:

*It was a hamm-handed [sic] attempt at humor.*