What is the explanation of this paragraph, and does a divorce take effect legally or religiously if the writing is unclear but accompanied by intention?

Scholars agree that divorce takes effect through writing if the husband intends it, because writing takes the place of verbal utterance. However, if there is no intention, it does not take effect according to the Hanafis, Malikis, Shafi'is, and some Hanbalis.

It is stipulated that the writing through which divorce takes effect must be clear and legible, and on a stable medium such as a paper or a wall. Divorce does not take effect through writing on air or water, because such writing is not considered clear and distinct.