Hi D.T.
This was your comment: Is it P's and Q's or Ps and Qs or p's and q's or ps and qs? What about this one? Ben wanted to yell Help but he was ashamed. Is it Help, "help," help, or what?
Those are interesting questions. I don't know about the US, but in Australia we have a helpful Commonwealth of Australia Style Manual, with lots of information for grammar geeks like me. The latest edition (2002, p. 88) says that the form p's and q's is the best one. Italics and no apostrophes are possible (ps and qs), but not so clear. In general, letters of the alphabet should take an apostrophe in the plural. Decades, however, have no apostrophe, so that the decade of the nineties is referred to as the 1990s. The Style Manual also says that 'most shortened words and phrases are made plural simply by adding s, without a preceding apostrophe' (pp. 152-153). That means we have MPs, TVs and CDs. By the way, we don't need to use full stops (periods) with contractions and acronyms, so that we have Mr (not Mr.) and NATO (not N.A.T.O.). We do have full stops when an abbreviation consists of only the first letter of a word, such as p. (page) or fig. (figure).
That also reminds me of the difference between ed. (editor) and edn (edition), where ed. takes a full stop because 'd' is not the last letter, but end has no full stop because 'n' is the last letter of the word!
Some Latin short forms seem to keep the full stop: e.g., et al., etc., but not MS (manuscript), NB (take note) or PS (postscript), all of which are written in capitals. How does that sound? As clear as mud? (That's a British English expression whose meaning you can probably guess!)
In regard to the second question about yelling 'help', I think I'd say:
Ben wanted to yell 'Help!', but he was ashamed. This is similar to the example in the Style Manual (p. 116): He heard the Speaker call 'Order!'
In that case it's a direct quote, so you can use quotation marks.
Have fun writing, and don't forget to dot your i's and cross your t's!
Julia