[xzins]

Must he specifically say that he is "intending to bind the church with definitive teaching?"

[Campion]

There's no exact formula or specific language required, but yes, he needs to be clear that this isn't a subject for debate, subject to change, just an opinion, or anything like that.

A technical term that's sometimes used is de fide definita, "a definition of or pertaining to the faith". Another term you'll see is a requirement that something must be "believed with divine and Catholic faith".

[Alex Murphy]

Must he specifically say that he is "intending to bind the church with definitive teaching?"

Not only that, but I hear he must wear the correct hat the entire time, too.

[Campion]

Here's a good example of definitive teaching on a matter of faith and morals:

Wherefore, in order that all doubt may be removed regarding a matter of great importance, a matter which pertains to the Church's divine constitution itself, in virtue of my ministry of confirming the brethren (cf. Lk 22:32) I declare that the Church has no authority whatsoever to confer priestly ordination on women and that this judgment is to be definitively held by all the Church's faithful. (Pope John Paul II, Ordinatio Sacerdotalis, May 22, 1994)

I should point out that theologians asked the Vatican directly whether this was a true ex cathedra Papal definition, and the reply was negative, with the explanation being that it was re-stating something that was already infallibly known.