Holy cow, I wrote a book!
In his reddit AMA,
i have regular 1-1 meetings with my counterparts in Office, Skype, Xbox.
The little bit of jargon there is
This is an abbreviation for
a common business practice wherein
a manager and a direct report,
have a face-to-face meeting with no one else present.
In the case Joe used,
the meeting is not between a manager and a direct report
but between two peers.
The term is also abbreviated 1:1,
which like 1 − 1
also looks like a bit of mathematical nonsense.
But it's not zero or one.
It's just an abbreviation for business jargon.
Of course, Microspeak isn't happy with the abbreviation as-is.
Microspeak takes it further and nounifies the abbreviation.
"I'll bring that up in my 1–1 with Bob tomorrow"
"I'll bring that up in my one-on-one meeting with Bob tomorrow."
Note that the abbreviation OOO is not used
to mean one-on-one.
That abbreviation is used to mean Out of the office,
although it is more commonly abbreviated