The merger agreement between Elon Musk and Twitter has a very unusual provision. It specifically preserves Musk’s right to tweet about the deal.

The merger agreement, which was filed with regulators on Tuesday evening, forbids the parties from issuing press releases or making statements about the deal without consulting each other. That’s a very standard provision for a corporate takeover.

What’s not standard is the provision that says this rule does not apply to Musk’s tweets.

“Notwithstanding the foregoing, the Equity Investor shall be permitted to issue Tweets about the Merger or the transactions contemplated hereby so long as such Tweets do not disparage the Company or any of its Representatives,” the agreement says.

So Musk has accepted some limits to his tweets but got Twitter to explicitly agree he could tweet about the deal as long as he doesn’t insult them.