ice cream … would you like a hyphen with that?

Lower case ‘a’ from Adobe Caslon Pro, superpos...

Lower case ‘a’ from Adobe Caslon Pro, superposed onto some guides. (Photo credit: Wikipedia)

Hyphenation of words or linked words is so variable, that if you are a publisher, you really need to have your preferences highlighted in your style guide. As the language evolves, many words that took hyphens become compound words without hyphens, but in the process, many still linger between the two. Do you write co-operate and co-ordinate or cooperate and coordinate? Is it ice cream or ice-cream (whatever way you put it, the latter still tastes nice!).

The Cambridge Guide to English Usage (Pam Peters) is an excellent guide comparing US, UK and Australian English Usage, and I will quote from it here in reference to hyphen usage.

Though there are few fixed conventions over hyphens, authorities do agree on such underlying principles as: 

  • restrict the use of hyphens as far as possible
  • shed the linking hyphen from the better established formations
  • use hyphens to separate letter sequences which distract the reader from construing the word correctly

The guide goes on to enumerate a number of general rules for ‘hard hyphens’ as opposed to ‘ soft hyphens’ that are used to break a word at the end of a line.
1. Complex words with prefixes are not normally hyphenated, but set solid. For example, amoral, debrief, cohabit. In some cases, however, as with co- and ex- it depends on whether the word is an older or newer type of formation. Other exceptions … are a) using a hyphen when the prefix ends in the same vowel as as the first letter of the root word, as in : anti-intellectual and de-emphasise. b) introducing a hyphen in formations which would otherwise be identical with another word (as in re-cover). c) using a hyphen when the following word involves a change in typography, such as capital letters, numbers, to or from italics, or quotation marks.
2. Compounds – Compound verbs … consisting of a noun + verb (baby-sit) are typically hyphenated. Compound adverbs are usually set solid (barefoot, downstairs, overboard). Compound adjectives are typically hyphenated (tone-deaf, red-hot, icy-cold, nuclear-free). Compound nouns can be written with hyphens, spaced, or set solid, depending somewhat on what they consist of. 
It goes on to enlarge on the above, with various exceptions and combinations. If we go back to the question in my title of ice cream, what is the answer? It is a noun compound that can be applied spaced or with a hyphen depending on what dictionary you use and what applies in the style guide of the publication you may write for.
I hope this gives some clarification to the usage of hard hyphens, while it will raise plenty of questions, I’m sure.