Title-Casing "ad hoc"
Let's say there's an article or a book titled solutions for ad hoc problems in foobar. How is ad hoc title-cased? As a preposition ad with a pronoun hoc or as an adjective? I mean, which of these four is correct?
- Solutions for Ad Hoc Problems in Foobar
- Solutions for Ad hoc Problems in Foobar
- Solutions for ad Hoc Problems in Foobar
- Solutions for ad hoc Problems in Foobar
I see that English dictionaries tend to list is as adjective/adverb which suggests Ad Hoc. But also, if treated as an adjective, it shall have a hyphen, which is clearly wrong.
(Note that I just copy-edit other people's work so I can't remove the phrase from the title, which could be an option...)
This is a question about publishing conventions, not the English Language. Title casing isn't a linguistic issue, in the same way that "How to best perm my dog's hair" doesn't come under "Biology".
So, as with all convention-based questions, we look to see what other people tend to do. For example, search Amazon Books for "ad hoc". This reveals a number of titles:
https://www.amazon.co.uk/s/ref=nb_sb_noss?url=search-alias%3Dstripbooks&field-keywords=ad+hoc&rh=n%3A266239%2Ck%3Aad+hoc
Generally, these say "Blahing With Ad Hoc Blah". So, you should probably go with "Ad Hoc".
To my thinking, this is more a case of making a style choice for Latin locutions than it is determining correct English language usage. I therefore suggest "ad hoc" is best presented in lowercase italics:
- Solutions for ad hoc Problems in Foobar
If you prefer to ignore the non-English aspect, the AP style guide for title case says this:
Don’t capitalize articles, prepositions or conjunctions that have fewer than four letters.
Because ad is a preposition and hoc is a pronoun, the former should be capitalized and the latter should not.