Use this attribute only when you want the browser to evaluate the script in a language or a version of the language other than the default. If the browser does not support the specified language or version of the language, the script will not be evaluated.
- See the lang attribute if you want to declare the natural language of your content, eg. French, etc.
- When a type attribute is also specified, it takes precedence over this attribute and this attribute will be ignored.
Microsoft Developer Network: [Windows Internet Explorer API reference Article]