I've been reviewing my FrameMaker source files for Fastware!, looking out for single-sourcing no-nos. High on the list is the use of physical styles instead of logical ones, the poster child for which is the use of italics to style text instead of a logical style like "Book Title." The problem is that the use of italics can be for emphasis, for the title of a publication, for the introduction of a new term, and more. A well-styled manuscript will use only logical style names -- never raw italics.
Alas, nearly every authoring system I know goes out of its way to make it easy to italicize text. WYSIWYG systems (at least those on Windows) define ^I to mean "italicize the selection", HTML offers \i, LaTeX has \it, reST offers *text*, etc. It's a similar situation for making things bold or underlined, both of which are also physical styles and should thus be avoided.
From what I can tell, there is no notion of "italicization" in the DocBook or DTBook schemas, and the screen shot for oXygen's XML Author for DocBook shows a toolbar button only to emphasize text, not italicize it. Score one for XML.
I've decided to use FrameMaker, not XML, so I'll be working in WYSIWYGland. I'm still committed to using only logical styles, and although I'm a pretty disciplined guy, I have no illusions that I'm perfect. If I don't find a way to keep myself from doing it, I know I'll occasionally type ^I (or ^B for bold) in FrameMaker without thinking about it. I won't notice my formatting faux pas (note use of italics to indicate a foreign expression, which is quite different from using them to emphasize something or to indicate a book title), because everything in my WYSIWYG world will look right. The situation would likely be the same in an italics-supporting markup-based world such as LaTeX or reST.
Fortunately, FrameMaker's keyboard and menu command set is determined by configuration files, so, with some guidance from the kind folks at the FrameMaker forum, I was able to excise keyboard and toolbar commands for italics, bold, and underlining. Now, should I foolishly try to italicize something via the errant ^I, nothing happens.