The hint for `move_semantics5` refers to "the range in which each
mutable reference is in vogue". Unless this is a deliberate
introduction of "vogue" (an admittedly-useful term because "scope"
isn't purely lexical, as in many other languages), it may be in error:
I have been unable to find the term used with reference to *Rust*
references.
Thus, I'm suggesting the replacement, in case it's been overlooked.
