The HTML Language - HTML Manual of Style - page 51

user's mouse hovered over the linked element. Users seemed to like tooltips,
and web developers provided them by enclosing elements in anchor tags with
null links just so that the tooltip would appear. Seeing the usefulness of the
title attribute to search engine robots, the HTML4 speciication extended its
application to all HTML elements.
he next two global attributes can be added to any element, but they are
most useful when used in user input ields and controls:
accesskey Speciies a shortcut key to be assigned to the element
to give it focus
tabindex Speciies the ordering of elements when tabbing
through a document
hese four HTML attributes are new with HTML5 and are designed to be
used with editable web page content:
contenteditable Speciies that the content may be editable if the host
permits such operation
contextmenu Speciies a menu that may be presented when the user
Alt-clicks the element
draggable Speciies whether the user may reposition the element
spellcheck Speciies whether the browser can spell-check the ele-
ment's content
hese last three HTML5 global attributes provide a means for HTML ele-
ments to be related to each other across the DOM in scripting applications:
subject Speciies that the element is the subject of an element
with a corresponding item attribute
item Speciies that the element is an item of an element
with a corresponding subject attribute
itemprop Speciies the properties of an element with an item
attribute
A number of HTML attributes existed before CSS. hese attributes are sup-
ported for backward compatibility even though web authors are encouraged to
use CSS in their place.