The br element: part of review of "Prose" section (currently 3.9)

The br element: part of review of "Prose" section (currently 3.9)
<http://dev.w3.org/cvsweb/~checkout~/html5/spec/Overview.html? 
rev=1.78#the-hr

Element-specific attributes
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Consider adding a @level (integer) attribute. This would provide a  
semantic hook in the document for styling languages. Sometimes a  
break may represent only a line break. Other times a break may be a  
column break, page break, section break, etc. By adding a @level  
attribute authors could use the particular levels to indicate how  
much of a break should occur. Normally, it would merely indicate a  
line brea. However, other break levels could indicate to start a new  
column, or start a new page. The @level attribute would provide a  
presentation independent way to express that semantically and provide  
a mechanism for presentation languages such as CSS to style the  
document appropriately.