When are hyphens required to string together a sequence of words, and when are the hyphens extraneous? The following sentences, each with a discussion and a revision, illustrate the syntactical situations in which they are necessary and when they are superfluous.
1. Who was the behind the scenes negotiator who facilitated the deal?
The negotiator is described as working behind the scenes. When that phrase appears in isolation, as an adverbial phrase rather than as a phrasal adjective modifying a noun that follows, no hyphenation is needed, but here, it serves the latter function: “Who was the behind-the-scenes negotiator who facilitated the deal?”
2. There is no “one size fits all” list of risk concerns.
Enclosing a phrase like this implies that the phrase is obscure and requires scare quotes or that someone said it and so quotation marks are needed, but the expression is ubiquitous, and no speaker is alluded to. To signal that those four words combine to modify list, string them together with several hyphens: “There is no one-size-fits-all list of risk concerns.”
3. Jones was forced out-of-bounds on the deciding play.
The adverbial phrase “out of bounds” requires no linkage to indicate that it is self-contained; it modifies the verb it follows, not a subsequent noun: “Jones was forced out of bounds on the deciding play.”
4. She has an annoying in your face attitude.
The phrase “in your face” modifies attitude as a single unit, so the phrase should be hyphenated: “She has an annoying in-your-face attitude.”
5. It has recently become a most-favored-nation among many countries in the European Union.
When “most-favored nation” appears in isolation, it should appear just as it does within the quotation marks in this explanatory sentence; “most favored” is a phrasal adjective modifying nation: “It has recently become a most-favored nation among many countries in the European Union.” (Nation joins the hyphenation train only when it loses its noun status and joins the phrasal adjective to modify another noun, as in “most-favored-nation status.”)