Implementation-defined behavior (Definition)

Correct behavior that is specific to a particular implementation.

Some behavior falls outside the ECMAScript standard but is nevertheless correct. Implementers should try to adhere to the spirit of the standard as far as possible. If other standards are built into the implementation (such as DOM for example), the standards working groups generally try to make the standards interoperable, and this helps to make sure that an implementation can support them both easily.

It is important that the implementers properly document any implementation specific behavior.

See also:Behavior, Host environment, Host object, Implementation-supplied code, Implementation-supplied function