I was unclear. You're saying that editor content can be exported in various formats. But I'm wondering if the editor has an explicit schema that it uses to guid

I was unclear. You're saying that editor content can be exported in various formats. But I'm wondering if the editor has an explicit schema that it uses to guide & restrict the editing process, so that I can have the editor generate only a customised/restricted version of HTML, or even a different markup language schema entirely (such as Docbook).