As I understand it, basically the 'self-closing tags' are considered valid markup, but this comes under WHATWG's philosophy of trying to be inclusive as much ex

As I understand it, basically the 'self-closing tags' are considered valid markup, but this comes under WHATWG's philosophy of trying to be inclusive as much existing markup that is out there as possible (within reason). This is in opposition to the strictness of XHTML's approach. This post by hixie indicates that self-closing tags are allowed to 'ease migration': http://lists.whatwg.org/pipermail/help-whatwg.org/2008-August/000137.html http://lists.whatwg.org/pipermail/help-whatwg.org/2008-Augus... I believe the 'spirit' of the spec would imply that <br> is the best practice when writing new markup. HTML5 maintains no pretence of being XML.