When the ScriptEngineMinorVersion function is called, it returns a value that identifies the minor revision level of the implementation, not the revision level of the ECMAScript or JavaScript language specification that is currently supported by the implementation. This return value cannot be used as a reliable indicator of the availability or lack of availability of specific language features.

The ECMAScript implementation within Microsoft Internet Explorer 9 always returns a value of 0, even when Internet Explorer 9 is operating in Quirks, IE7, or IE8 document modes.