Disabling HTML in Description?

I would like to know the answer to this as well.

In the development version you can use filters and actions to add a custom editor. There is an example included (Showtime) which does exactly what you want.

I have tried this with Showtime in the development version, and I am still able to enter html into the description.

I am running the development version, and added a new post with https://mysite.com/new-post?showtime_taxonomy=Showtime-120
and was able to enter html into the description.

Am I doing something wrong or missing something?

Thanks!