Legacy IE non-standard support In order to support web pages designed for legacy versions of Netscape and Internet Explorer, Gecko supports DOCTYPE switching. Documents with a modern DOCTYPE are rendered in standards compliance mode, which follows the W3C standards strictly. Documents that have no DOCTYPE or an older DOCTYPE are rendered in quirks mode, which emulates some of the non-standard oddities of Netscape Communicator 4.x; however, some of the 4.x features (such as layers) are not supported.
Legacy IE non-standard support In order to support web pages designed for legacy versions of Netscape and Internet Explorer Gecko supports DOCTYPE switching Documents with a modern DOCTYPE are rendered in standards compliance mode which follows the W3C standards strictly Documents that have no DOCTYPE or an older DOCTYPE are rendered in quirks mode which emulates some of the non-standard oddities of Netscape Communicator 4x; however some of the 4x features (such as layers) are not supported