7.1 How to trigger Quirks Mode emulation

Quirks Mode emulation is used in the following circumstances:

  • A page in IE9 Mode loads a Quirks Mode HTML page in an iframe.

  • A frameset in IE9 Mode loads Quirks Mode content in a frame.

Only content in child pages is rendered using Quirks Mode emulation. Windows Internet Explorer continues to render the containing document in IE9 Mode.

Quirks Mode emulation is not used when loading child pages that specify a standard <!DOCTYPE>, or those that use the X-UA-Compatible meta tag to specify support for Windows Internet Explorer 8, Windows Internet Explorer 9, or EdgeHTML Mode. These pages are rendered with IE9 Mode instead. For more information about how Internet Explorer selects Document Mode, see [MS-IEDOCO] section 2.1.3.