The Mozilla browser, like several other browsers on the market, uses DOCTYPE sniffing to determine how to render a page. In Mozilla's case, it either renders the page strictly, in "standards mode," or more loosely -- otherwise known as "quirks mode." Now Mozilla introduces something more.
In the upcoming 1.01 and 1.1 releases, Mozilla will add an "almost standards" mode to its mix. This mode is virtually identical to the standards mode (now being referred to as "full standards mode") but with one crucial change. In almost standards mode, Mozilla will not implement the CSS-2 line-height rules that causes many pages with pixel-precise image layouts via tables to break apart.
Several DOCTYPEs that formerly triggered full standards mode will now render in almost standards mode. Those DOCTYPEs are: