July 2014 UTC I didn t say that the summary attribute is not working I said that it was marked as obsolete Obsolete in this instance means that browsers claiming compliance with HTML 5 need not support it and people writing pages that claim compliance with HTML 5 should not use it But most browsers that support HTML 5 also support HTML 4 not just because it will take a long time for everybody with a website to rewrite the content for HTML 5 if it ever happens there are still a lot of HTML 2 0 or 3 2 compliant pages out there that would fail a conformance check for HTML 4 let alone HTML 5 but also because HTML 5 has not yet reached the W3C Recommendation stage so the current stable standard is HTML 4 01 On some discussion pages I know of at least three threads outside of User talk space there is a scaremonger going around telling people to stop using the element ASAP because it s marked as obsolete in HTML 5 Don t panic it still works in every browser I ve tried it in though and will probably do so for a long time yet 07 42 28