NOTE: These results should NOT be taken as authoritative. DOCTYPE switching is a tricky thing to test, requiring more work than I've been able to plow into it. Consider the following information a rough guide at best, and subject to change as further testing warrants. Thank you.

EntryMeaning
QQuirks mode
AAlmost-standards mode
SStandards mode
-Status unknown

Last modified Monday 27 November 2006 16:59:47 (Eastern U.S.)

DOCTYPE givenNN6.xNN7.0Moz1.0IE5/MacIE6/WinIE7/Win
No DOCTYPE given Q Q Q Q Q Q
Unrecognized DOCTYPE Q S S S S S
Unrecognized DOCTYPE + URI Q S S S S S
HTML 2.0 Q Q Q Q Q Q
HTML 3.0 Q Q Q Q Q Q
HTML 3.2 Q Q Q Q Q Q
HTML 3.2 + URI Q Q Q Q Q Q
HTML 4.0 Strict S S S S S S
HTML 4.0 Strict + URI S S S S S S
HTML 4.0 Transitional Q Q Q Q Q Q
HTML 4.0 Transitional + URI Q Q Q S S S
HTML 4.0 Frameset Q Q Q Q Q Q
HTML 4.0 Frameset + URI Q Q Q S S S
HTML 4.01 Strict S S S Q S S
HTML 4.01 Strict + URI S S S S S S
HTML 4.01 Transitional Q Q Q Q Q Q
HTML 4.01 Transitional + URI S A S S S S
HTML 4.01 Frameset Q Q Q Q Q Q
HTML 4.01 Frameset + URI S A S S S S
XHTML 1.0 Strict S S S S S S
XHTML 1.0 Strict + URI S S S S S S
XHTML 1.0 Transitional S A S S S S
XHTML 1.0 Transitional + URI S A S S S S
XHTML 1.0 Frameset S A S S S S
XHTML 1.0 Frameset + URI S A S S S S
XHTML 1.0 Strict w/XML S S S S Q S
XHTML 1.0 Strict w/XML + URI S S S S Q S
XHTML 1.0 Transitional w/XML S A S S Q S
XHTML 1.0 Transitional w/XML + URI S A S S Q S
XHTML 1.0 Frameset w/XML S A S S Q S
XHTML 1.0 Frameset w/XML + URI S A S S Q S
Any XML S S S S - -
Any XML + URI S S S S - -