Using the full form (attribute="attribute") of boolean attributes rather than the minimized form is recommended. The full form will be properly understood by web browsers parsing polyglot documents as either the HTML syntax or the XML syntax of HTML 5.
<input type="text" readonly="readonly"/><input type="text" required="required"/><option selected="selected"/><video autoplay="autoplay" ...>
These are the common (global) attributes that can be used on various HTML tags.
The class attribute
<p class="centered">Alignment of this paragraph will be determined by the settings of the ".center" style.</p>
Although it is a misuse of the class attribute, Google Translate recognizes the specific value notranslate, indicating that the content of the element should not be translated into other spoken languages. http://www.Google.com/help/faq_translation.html#donttrans
<span class="notranslate">...</span>
The contenteditable attribute
<span contenteditable="">...</span>
The contextmenu attribute
<span contextmenu="">...</span>
<span data-latitude="40°19'N" data-longitude="79°59'35"W">...</span>
The dir attribute
<span dir="">...</span>
The draggable attribute
<span draggable="">...</span>
The id attribute
<span id="mytag">...</span>
The item attribute is used for "microdata", which can be machine-readable.
More information: item attribute
The lang attribute
<span lang="">...</span>
The spellcheck attribute
<span spellcheck="">...</span>
The style attribute
<span style="">...</span>
The tabindex attribute
<span tabindex="">...</span>
The title attribute
Line breaks within the title attribute in the source code are significant and will be included if the title is displayed.
<span title="">...</span>
The list of the event attributes include:
onabort
The onabort attribute
onbeforeonload
The onbeforeonload attribute
onbeforeunload
The onbeforeunload attribute
onblur
The onblur attribute
oncanplay
The oncanplay attribute
oncanplaythrough
The oncanplaythrough attribute
onchange
The onchange attribute
onclick
The onclick attribute
oncontextmenu
The oncontextmenu attribute
oncopy
The oncopy attribute
oncut
The oncut attribute
ondblclick
The ondblclick attribute
ondrag
The ondrag attribute
ondragend
The ondragend attribute
ondragenter
The ondragenter attribute
ondragleave
The ondragleave attribute
ondragover
The ondragover attribute
ondragstart
The ondragstart attribute
ondrop
The ondrop attribute
ondurationchange
The ondurationchange attribute
onemptied
The onemptied attribute
onended
The onended attribute
onerror
On the body tag, the onerror attribute is a property of the document's window object. On other elements, the onerror attribute is a property of the HTML element itself.
onfocus
The onfocus attribute
onformchange
The onformchange attribute
onforminput
The onforminput attribute
ongesturechange
The ongesturechange attribute
ongestureend
The ongestureend attribute
ongesturestart
The ongesturestart attribute
oninput
The oninput attribute
onkeydown
The onkeydown attribute
onkeypress
The onkeypress attribute
onkeyup
The onkeyup attribute
onload
On the body tag, the onload attribute is a property of the document's window object. On other elements, the onload attribute is a property of the HTML element itself.
onloadeddata
The onloadeddata attribute
onloadedmetadata
The onloadedmetadata attribute
onloadstart
The onloadstart attribute
onmousedown
The onmousedown attribute
onmousemove
The onmousemove attribute
onmouseout
The onmouseout attribute
onmouseover
The onmouseover attribute
onmouseup
The onmouseup attribute
onmousewheel
The onmousewheel attribute
onmove
The onmove attribute
onorientationchange
The onorientationchange attribute
onpaste
The onpaste attribute
onpause
The onpause attribute
onplay
The onplay attribute
onplaying
The onplaying attribute
onprogress
The onprogress attribute
onratechange
The onratechange attribute
onreadystatechange
The onreadystatechange attribute
onreset
The onreset attribute has been deprecated in HTML 5 and should not be used.
onresize
The onresize attribute
onscroll
The onscroll attribute
onseek
The onseek attribute
onseeking
The onseeking attribute
onselect
The onselect attribute
onshow
The onshow attribute
onstalled
The onstalled attribute
onsubmit
The onsubmit attribute
onsuspend
The onsuspend attribute
ontimeupdate
The ontimeupdate attribute
ontouchcancel
The ontouchcancel attribute
ontouchend
The ontouchend attribute
ontouchmove
The ontouchmove attribute
ontouchstart
The ontouchstart attribute
onunload
The onunload attribute
onvolumechange
The onvolumechange attribute
onwaiting
The onwaiting attribute
<span onclick="">...</span>