Although there are plenty of grammar topics that I occasionally struggle with, there is one that causes the most trouble. Lately, I have been writing a lot of technical instructions and manuals, in which it's very common to use noun+noun structures like notification service or account management. In some cases, however, it is not clear whether a singular or plural noun should be used as a modifier. I have searched the indispensable CGEL, but it only says that nouns that are used this way are not, technically speaking, adjectives and it would be more accurate to describe them as pre-head modifiers.
This is all very well, but are there any rules or guides that define the correct use of such expressions? I remember reading in some technical guide that similar phrases should be looked up in a dictionary. Unfortunately, I don't remember the name of that guide :)
Could you please elaborate on this. Thank you.