A turn of the document
Not a formal term, but the one people use to say where a negotiation has got to and whose move it is.
What it means
A turn is one party's round of revisions to a document, passed back to the other side. The first draft goes out, comes back marked up — that is a turn — goes out again with responses, and so on until nobody has anything left to change.
"We're on the third turn" says roughly how far along a negotiation is. "It's with them" says whose move it is. Neither is a term of art; both are used constantly, because the alternative phrasings are all longer.
Why the word is useful
It counts the thing worth counting. Versions accumulate for all sorts of reasons — someone saves twice, a schedule is updated separately, an internal draft circulates — but a turn is an exchange, and an exchange is what costs time. A document on its sixth turn is in a different state from one on its second, whatever the version numbers say.
It also frames what a comparison is for. When a turn comes back, the first question is what they changed since the version you sent, which is a comparison between two specific drafts: yours as sent, and theirs as returned. Not the first draft, and not the version saved in between.
What a turn contains
Conventionally, a turn is sent as a clean copy and a redline against the version received, sometimes with a short covering note listing the substantive points. The redline is against what they were sent, not against the first draft, unless somebody says otherwise.
Where that convention slips — a turn arrives clean, or marked up against the wrong version — running your own comparison is quicker than asking, and it answers the question you actually have rather than the one they thought you had.