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Meta tag X-UA-Compatible

Meta tag X-UA-Compatible controls the mode of displaying pages in browsers IE8 +

Syntax

<meta http-equiv="X-UA-Compatible" content="..." />

Values ​​for IE8 +

Tag value Description of the mode of operation of IE8 + Mode code name
IE = 5 Displaying content in IE5 compatibility mode displays pages as IE5.5 does, regardless of whether the page contains a <! DOCTYPE> directive, Quirks mode (compatibility mode)
IE = 7 Displaying content in standard IE7 mode, displays pages in the same way IE7 does, regardless of whether the page contains a <! DOCTYPE> directive, IE 7 Standards mode (standard IE7 mode)
IE = EmulateIE7 forces IE to use the <! DOCTYPE> directive to specify how the content is displayed. The standard mode directives are displayed in the standard IE7 mode, and compatibility mode directives are displayed in IE5.5 (Quirks) mode. IE 7 Emulation mode (IE7 emulation mode)
IE = 8 Displaying content in the standard IE8 mode, displays pages in the same way IE8 does, regardless of whether the page contains a <! DOCTYPE> directive, IE 8 Standards mode (IE8 standard mode)
IE = EmulateIE8 forces IE to use the <! DOCTYPE> directive to specify how the content is displayed. The standard mode directives are displayed in the standard IE8 mode, and compatibility mode directives are displayed in IE5.5 (Quirks) mode. IE 8 Emulation mode (IE8 emulation mode)
IE = edge always uses the last available standard display mode, regardless of <! DOCTYPE>. Edge mode (last mode)

Values ​​added in IE9

Tag value Description of the IE9 mode Mode code name
IE = 9 Displaying content in IE9's standard mode displays pages as IE9 does, regardless of whether the page contains a <! DOCTYPE> directive, IE 9 Standards mode (IE9 standard mode)
IE = EmulateIE9 forces IE to use the <! DOCTYPE> directive to specify how the content is displayed. The standard mode directives are displayed in the standard IE9 mode, and compatibility mode directives are displayed in IE5.5 (Quirks) mode. IE 9 Emulation mode (IE9 emulation mode)

If the directive not specified, IE behaves as if the Compatibility Mode directive (Quirks DOCTYPE) is specified.

Example

<meta http-equiv="X-UA-Compatible" content="IE=EmulateIE7" />

The tag must be in the head section of the page before all other elements, except for the title and other meta-elements. Otherwise it is ignored!