HTML and CSS Reference
Even if you know that you'll be “unhiding” stuff later with some
scripting, you should treat hidden stuff as if it literally wasn't
there. So don't add links pointing to content that's hidden
and don't tie other elements to it with aria-describedby or
Yo u id o n ' t n e e id u is. t o e x p l a i n w h a t o u r o l id c h u m id is. But now
you can begin the value of id with a digit, just like you always
have been able to do with class . Yay to the max, that's phat,
as people a quarter of my age probably say.
itemtype, itemref, itemid
These attributes are associated with the Microdata specification.
As you've already seen, HTML5 treats WAI-ARIA as legal addi-
tions to the language—meaning they'll quite happily validate.
This Boolean attribute tells the browser to check the element's
spelling and grammar—generally, an <input> or <textarea> ,
but it could be anything because anything can be set to be
contenteditable . If it's missing, “the default state indicates that
the element is to act according to a default behavior, possibly
based on the parent element's own spellcheck state.”
tabindex is a largely archaic concept that allows you to specify
the order in which elements are focused when the user navi-
gates a page with the keyboard (traditionally using the Tab key,
though some browsers—most notably Opera—may use different
key combinations for this).
This was quite popular when sites were built using deeply
nested layout tables in which the document order of focus-
able elements would often be markedly different from its visual