What are we trying to solve with document.designMode?

Hello,

I was looking at behavior differences between browsers and the spec regarding document.designMode.

The way the attribute is defined in the spec makes it just another way to formulate contentEditable for the document. With such a definition, it seems overkill to have it since there are already 2 more generic ways to express the same thing: contentEditable and CSS's user-modify.

The implementation differs from the specification in the sense that you cannot override the designMode by a child with contentEditable. See:
-https://bugs.webkit.org/show_bug.cgi?id=22036
-https://bugzilla.mozilla.org/show_bug.cgi?id=462735

According to its documentation, the way designMode works on Internet Explorer is yet another behavior: http://msdn.microsoft.com/en-us/library/ms533720%28VS.85%29.aspx

With my current understanding of the problem, I think this should be removed from the specification or explicitly deprecated. The differences between released browser make the attribute unreliable for web authors. I could not find in the archives why designMode was added to the spec, I would be interested to the rationale behind this feature.

cheers,
Benjamin