I've set the profile to user group Superusers and user to myself, set the text filter to none on superusers in global config, set iFrame to allowed in Media tab, and html cleanup is set to yes with an exception for iFrame. I am in code view, copy/paste the iFrame code (as from a Facebook video), hit Save. The code is still there so long as I don't Save & Exit, and then come back into the article in html view. If I come back in using code view, the iFrame code is still there. But I don't have a way to make sure code view was the last way I viewed an article.
To reiterate:
1. Place iFrame code in code view, Save, switch to html view, the iFrame code is gone.
2. Place iFrame code in code view, Save & Exit. Edit another article, having left it in html view. Open iFrame article, and now it opens in html view, and the iFrame code is gone in code view.
What else is there? Thanks for any support you can give.