Changes in HTML 5 - <hr> Tag
What's new in HTML 5
Differences between HTML 5 and earlier versions of HTML
The following attributes should not be coded on the <hr/> tag because they either have been deprecated or were never officially supported:
align
noshade
size
width
In ployglot HTML documents the <hr/>
tag is coded as a self-closing tag the same as in the 2000-2010 Recommendations from the W3C HTML Working Group. Those specifications changed the ending delimiter to />
from >
in older recommendations. They also defined the HTML namespace for the hr element type name and the names of other HTML element types.