No. Or rather; that would be pretty horrible html from a semantic standpoint -- and perhaps more importantly, it would need parsing into text anyway -- so might as well be more explicitly different from html.
That said, html5 is pretty free in terms of what you put in the document -- personally I'd probably prefer a "weight" or "weight-group" attribute applied to elements and/or set on span-elements. Weight might be a float between 0.0 and 1.0 (pick one to be most important, maybe let "heavy" weights "sink to the bottom", and "fall off"... ?) -- the idea of a "weight-group" would be to group headers and/or phrases/paragraphs to be dropped together -- eg for this comment, you might want to drop all references to "weight-group" -- if you wanted a shorter, simpler version.
Too far down this path and you're square in natural language processing territory -- but it should be easy to mock up a web app that lets the author/editor preview how different versions would render/look -- and allow adding/removing tags/weights to the text(s) as appropriate.
Perhaps one useful extension would be auto-promoting a paragraph and/or (depending on format/space) part of a paragraph, or just a header -- to be used as a "deck" and/or summary (for eg rss feeds) etc?
That said, html5 is pretty free in terms of what you put in the document -- personally I'd probably prefer a "weight" or "weight-group" attribute applied to elements and/or set on span-elements. Weight might be a float between 0.0 and 1.0 (pick one to be most important, maybe let "heavy" weights "sink to the bottom", and "fall off"... ?) -- the idea of a "weight-group" would be to group headers and/or phrases/paragraphs to be dropped together -- eg for this comment, you might want to drop all references to "weight-group" -- if you wanted a shorter, simpler version.
Too far down this path and you're square in natural language processing territory -- but it should be easy to mock up a web app that lets the author/editor preview how different versions would render/look -- and allow adding/removing tags/weights to the text(s) as appropriate.
Perhaps one useful extension would be auto-promoting a paragraph and/or (depending on format/space) part of a paragraph, or just a header -- to be used as a "deck" and/or summary (for eg rss feeds) etc?