HTML and CSS Reference
• The hgroup element is used to control the HTML5 sectioning algorithm. Its primary
purpose is to collapse elements that would normally add outline entries into a
single entry. For example, when multiple headings ( h1 - h6 ) are used, they will
individually add items to the outline. By containing headings together in the
hgroup element, they form only a single entry in an outline. As demonstrated in the
preceding example, the need for this element is mostly to support subheadings.
• This element was added much later than many other HTML5 elements, and there is
some controversy over what it should be called.
• While this element is not yet supported, it is easily simulated by using a custom tag
or using a <div> tag with a special class.
<hr> (Horizontal Rule)
This element is used to insert a horizontal rule to visually or thematically separate
document sections. Rules usually are rendered as a raised or etched line.
align="center | left | right" (transitional only)
dir="ltr | rtl"
id="unique alphanumeric identifier"
lang="language code"id="unique alphanumeric identifier"
noshade="noshade " (transitional only)
size="pixels" (transitional only)
width="percentage | pixels"> (transitional only)
Attributes Introduced by HTML5
accesskey="spaced list of accelerator key(s)"
contenteditable="true | false | inherit"
contextmenu="id of menu"
draggable="true | false | auto"
itemid="microdata id in URL format"
itemref="space-separated list of IDs that may contain microdata"
itemtype="microdata type in URL format"
spellcheck="true | false"
Attributes Defined by Internet Explorer
color="color name | #RRGGBB" (4)