• They are a couple.
• It is a retreat for couples.

In others, you cannot:

• I will list a couple of examples here.
• She has a couple of books in her house.

Here’s the key: replace couple with pair, and see if you need of:

• They are a pair.
• NOT: They are a pair of.
• It is a retreat for pairs.
• NOT: It is a retreat for pairs of.
• I will list a pair of examples here.
• NOT: I will list a pair examples here.
• She has a pair of books in her house.
• NOT: She has a pair books in her house. (We’ll disregard the fact that “couple” in this usage was probably not meant to be literal.)

End o’ the rant. Please carry on.

I’m well aware that as dictionaries continue their slide away from being a place you can go to find out how you should use some word, and toward simply being wikis of every conceivable way in which the word is used, you will be able to find some sort of “dictionary” that disagrees with these, but ask yourself this: Do you really want to be seen as using constructions that most reputable sources will call “substandard” or “dialectal” or “idiomatic”?

The word “comprise” means to bring together, to include, to be made of, as in:

• The committee comprises the heads of all the departments.
• The article on the blog comprises three distinct parts.

It does not simply replace “made,” as in:

• The committee is comprised of the heads of all the departments.
• The article on the blog is comprised of three distinct parts.

Today, I came across another use of the term: “The article comprises of these separate parts…” Sort of a compromise, I guess, but a compromise is a situation where all parties are equally unhappy.

References:

It is very disconcerting to see the number of times a source that is supposed to be a standard of usage says something like “Usage number X is considered as wrong, although there is no reason why it should be” (emphasis added). Um, because the word has a meaning? Because if we allow meanings to slide, then soon we will have no language? Anyway, all of these sources do show that the comprising is done by the whole, from the parts, and not by the parts themselves.

http://dictionary.reference.com/browse/comprise

http://www.thefreedictionary.com/comprise

http://www.merriam-webster.com/dictionary/comprise

http://en.wiktionary.org/wiki/comprise

Nor is it an acronym or an initialization. It is simply a Latin word. Originally, it was almost invariably used in the phrase “in re,” meaning “in regard to.” From Wikipedia:

In re, Latin for "in the matter [of]", is a legal term used to indicate that a judicial proceeding may not have formally designated adverse parties or is otherwise uncontested. The term is commonly used in case citations of probate proceedings, for example, In re Marriage Cases; it is also used in juvenile courts, as, for instance, In re Gault.

For hints on the usages of a word, it can be handy to consult a thesaurus. From define.com:

From Moby Thesaurus II by Grady Ward, 1.0 [moby-thes]:
31 Moby Thesaurus words for "re": about, anent, apropos of, as, as for, as regards, as respects, as to, concerning, in connection with, in point of, in re, in reference to, in regard to, in relation to, in relation with, in respect to, of, on, pertaining to, pertinent to, referring to, regarding, relating to, relative to, respecting, speaking of, touching, upon, with regard to, with respect to

Notice that in none of the usages shown is there a colon after re.

With the surge in microblogging sites such as Twitter, and their requirement for brevity, it is becoming increasingly common to see things like this:

I need to read up re: my city.

Or even worse, like this:

I need to read up RE: my city.

If you would do this, then you should also do this:

I need food, shelter, etc: in order to survive.

Only use a colon after “re” if the sentence structure requires it.

If you would use a colon there if the word were “regarding,” then go ahead and use it, but in the middle of a sentence, where there is no grammatical construction requiring it, leave it out!

I need to read up re my city.

You’re trying to save characters, right?