... That's what market partitioning _is_ though, right?
The two parties could independently come to the conclusion that Apple shouldn't compete with Office, but actually discussing it (and documenting the discussion!) is a flagrant violation of U.S. anti-trust laws.
Partitioning the market is when you, well, partition the MARKET, meaning divide up potential BUYERS of your product with some other company selling a similar product, so that your company is effectively a monopoly within the subset of buyers that you were allocated.
'Market division or allocation schemes are agreements in which competitors divide markets among themselves. In such schemes, competing firms allocate specific customers or types of customers, products, or territories among themselves.'
'This primer briefly describes the most common antitrust violations and outlines those conditions and events that indicate anticompetitive collusion.'
If it's cost prohibitive then the solution is common carrier status to become like electrical distribution network.
If it's not cost prohibitive that then the solution is criminal prosecution. It doesn't matter whether or not there's a formal internal agreement; there's clearly intent and informal collusion.
Unfortunately I don't have the answer here. And it was 9 years ago so well beyond meaning other than an anecdote.
They are only used for public image and putting the legal department on the safe side when things go wrong.