The sectioning elements act quite literally as their name suggests: they define sections of the parent element. These sections can be thought of as child nodes whose headings fall under their parent heading, regardless of their rank.
Sections may contain headings of any rank, but authors are strongly encouraged to either use only h1 elements, or to use elements of the appropriate rank for the section’s nesting level.
For accessibility reasons, we recommend each sectioning element have a heading, even <aside> and <nav>, as shown below. If you don’t want these headings to be visible, you can always hide them with CSS.
It’s best if you use logical heading levels — <h1>–<h6> — at least until the new outlines are more widely supported.
Unfortunately, there is little support for the new outlining algorithms right now. Search engines may be experimenting with it in their crawling algorithms as you read this, but as far as we know, headings are treated just as they were before. You won’t be penalised for using them, even if you use multiple <h1>s (which have always been okay as far as the spec is concerned). Check out our HTML5 and Search Engine Optimisation article for more on search engines and HTML5.
If you have a title with subtitle(s) and other metadata associated with the section or article, place both the <hgroup> and the metadata within a single <header> element.
If you have a title with subtitle(s) or tag lines (i.e., more than one consecutive <h1>–<h6>), group them in an <hgroup>.
When grouping headings in an <hgroup> element, the outline algorithm will mask the lowest level all but the highest level heading in the group from the resulting document outline.
It can only contain a group of <h1>–<h6> element(s), and it should be used for subtitles, alternative titles, and tag lines.
Headings in a <legend>
In forms, the <legend> element represents a caption for the form fields within a <fieldset>. Before HTML 5.2, the content of a legend had to be plain text. Now, we can include heading elements.
Include the HTML5 shiv in the <head> of your page in a conditional comment and after any stylesheets.
<!--[if lt IE 9]>
<script src="components/html5shiv/html5shiv.js"></script>
<![endif]-->
Manual installation
Download and extract the latest zip package from this repositiory and copy the two files dist/html5shiv.js and dist/html5shiv-printshiv.js into your project. Then include one of them into your <head> as above.
"How to enable and tags in all major browsers
To make HTML5 video and audio tags work in all major browsers, simply add the following line of code somewhere in the of your document.
"
\"', 'tags':'html,video,audio,tags,browsers,html5,mobile',
'first_user_id':1615481, 'first_user_name':'vfowler', 'first_user_real_name':'Vernon Fowler', 'last_user_id':1615481, 'last_user_name':'vfowler', 'last_user_real_name':'Vernon Fowler',
'user_count':1, 'p_c_count':1, 'ann_count':0, 'i_c_count':0, 'page_comments':[],'annotations':[]}
var p_c = {'id':1599877, 'group_id':106643, 'link_id':82697916, 'g_l_id':'106643-82697916', 'user_id':1615481, 'user_name':'vfowler', 'user_real_name':'Vernon Fowler', 'content':'\"How to enable \<video\> and \<audio\> tags in all major browsers\\n\\nTo make HTML5 video and audio tags work in all major browsers, simply add the following line of code somewhere in the \<head\> of your document.\\n\<script src=\"http://api.html5media.info/1.1.4/html5media.min.js\"\>\</script\>\"'}
b.page_comments.push(p_c)
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var b = {'item_id':8990366, 'obj_type':1, 'obj_id':135026493, 'index':7, 'checked':false,
'group_id':106643, 'g_name':'html5_dev', 'link_id':135026493, 'g_l_id':'106643-135026493', 'url':'https://code.google.com/p/html5shiv/', 'title':'html5shiv - HTML5 IE enabling script - Google Project Hosting', 'desc':'', 'tags':'html5,ie,browsers,html,script,javascript,browser,minify',
'first_user_id':1615481, 'first_user_name':'vfowler', 'first_user_real_name':'Vernon Fowler', 'last_user_id':1615481, 'last_user_name':'vfowler', 'last_user_real_name':'Vernon Fowler',
'user_count':1, 'p_c_count':0, 'ann_count':2, 'i_c_count':0, 'page_comments':[],'annotations':[]}
var ann = {'id':2595450, 'content':'', 'group_id':106643, 'link_id':135026493, 'g_l_id':'106643-135026493', 'user_id':1615481, 'user_name':'vfowler', 'user_real_name':'Vernon Fowler', 'c_count':0, 'inline_comments':[]};
b.annotations.push(ann);
var ann = {'id':2595480, 'content':'', 'group_id':106643, 'link_id':135026493, 'g_l_id':'106643-135026493', 'user_id':1615481, 'user_name':'vfowler', 'user_real_name':'Vernon Fowler', 'c_count':0, 'inline_comments':[]};
b.annotations.push(ann);
_items.push(b);
window.addOnLoadListener(function(){new ContextMenu("leftColumn",{eventType:"click",backgroundColor:'#E0EDFE',color:'#000'})});
window.addOnLoadListener(function(){new AvatarPopup()});