The doctype used on this page is
Note: Be sure to observe the test that is applicable to the browser you are using.
The browser is in the Standards or Almost standards Quirks mode.
The browser is not in the Standards or Almost Standards mode. It is in the Quirks mode.
Standards if the blue rectangles are a couple of pixels taller than a line of text. Almost standards or quirks if the rectangles are 3px tall.
Red if quirks