MDN reader's guide

While we strive to make the documentation on MDN Web Docs as clear and readable as possible, it's inevitable that certain conventions or design choices may be confusing to newcomers to the content, or to people not yet familiar with recent design changes. This guide for readers will strive to answer those questions.

Specification status icons

In a number of places on MDN, such as landing pages and indexes, we use icons to indicate the specification status of an element, property, method, or even an entire API. Hovering your mouse over these icons should present you with a tooltip that explains what the icon means. If it doesn't, you can refer to this section to help understand them.

Non-standard; the item is not part of any standard specification.
Deprecated; the item is no longer recommended for use, even though specifications may still allow it for legacy reasons.
Obsolete; the item has been removed from specifications and should not be used. You should strive to remove any existing uses from your code.
Experimental; the item is currently being considered for specification, or may be part of an early draft of a specification, and is likely to be changed before it is accepted. You should not use these in production code without ensuring that your code will still work if this doesn't function as expected.

See also