Explanation of Terms

This article describes terms used in an element or attribute listing.


Availability tells the versions of Safari in which the element first appeared or was deprecated. Deprecated tags are not guaranteed to be supported in the future. Elements available in Safari for Mac OS X and Windows are not automatically available in iOS, and vice versa.

Support Level

Support Level tells the source of a given tag if it is not part of a W3C standard or otherwise supported by the majority of current browsers. The possible values are:

Tags may be shifted to other categories as time passes, particularly as tags are added to relevant standards.