Assertion:
Netscape and Opera and the added quotes thing: Spaces before AND after the begin tag are honored, which seems to be counter to how they are usually treated for other elements (for an example try "test <q> hello </q> test" and compare the result to the same test using the U element).

Example of U element with spaces between each tag instance: 'test1 <u> hello </u> test'
test1 hello test2

Example of Q element with spaces between each tag instance: 'test1 <q cite="http://www.shakespeare.com/"> hello </q> test'
test1 hello test2

Example of Q element with multiple consecutive spaces between each tag instance: 'test1    <q cite="http://www.shakespeare.com/">    hello    there    </q>    test'
test1 hello there test2