HTML and CSS Reference
In-Depth Information
• HTML5 returns the
start
attribute to ordered lists and adds the
reversed
attribute.
• Under the XHTML 1.0 specification, the
compact
attribute must have a quoted
attribute value:
<ol compact="compact">
.
• The HTML 3.2 specification supports only the
compact
,
start
, and
type
attributes.
• The HTML 2.0 specification supports only the
compact
attribute.
<optgroup> (Option Grouping)
This element specifies a grouping of items in a selection list defined by
option
elements so
that the menu choices can be presented in a hierarchical menu or similar alternative fashion
to improve access through nonvisual browsers.
Standard Syntax
<optgroup
class="class name(s)"
dir="ltr | rtl"
disabled="disabled"
id="unique alphanumeric identifier"
label="text description"
lang="language code"
style="style information"
title="advisory text">
option elements
</optgroup>
Attributes Introduced by HTML5
accesskey="spaced list of accelerator key(s)"
contenteditable="true | false | inherit"
contextmenu="id of menu"
data-X="user-defined data"
draggable="true | false | auto"
hidden="hidden"
itemid="microdata id in URL format"
itemprop="microdata value"
itemref="space-separated list of IDs that may contain microdata"
itemscope="itemscope"
itemtype="microdata type in URL format"
spellcheck="true | false"
tabindex="number"
HTML 4 Event Attributes
onclick, ondblclick, onkeydown, onkeypress, onkeyup, onmousedown,
onmousemove, onmouseout, onmouseover, onmouseup
HTML5 Event Attributes
onabort, onblur, oncanplay, oncanplaythrough, onchange, onclick,
oncontextmenu, ondblclick, ondrag, ondragend, ondragenter, ondragleave,
