I have a database collection and several of the fields are rich text fields. When I open the rich text editor on one of these fields, there is no html-tab. So I have no possibility to edit the html-code directly. The problem appeared to another user, too: I found a post here:
However, there was no terminal solution for the problem (at least not for the public) and no one replied to my comment on this post. That's why I started a new one.