CSS validation, -moz extensions?

My CSS does not validate at
http://jigsaw.w3.org/css-validator/

Attempting to validate, for example, my

http://www.math.ufl.edu/~squash/course.advcal.2008t.html

produces (lightly edited)

/--------------------------------------------------------\
URI : http://www.math.ufl.edu/~squash/CSS/jkall.css
199 .BOOKEMF
Property -moz-border-radius doesn't exist : 20pt


URI : http://www.math.ufl.edu/~squash/CSS/jkselection.css
20 The pseudo-element
::-moz-selection can't appear here in the context css21

25 The pseudo-element
::selection can't appear here in the context css21

30 The pseudo-element
::-moz-selection can't appear here in the context css21

34 The pseudo-element
::selection can't appear here in the context css21
\_________________________________________________ _______/


Running firefox on MacOS, it appears that
"-moz-border-radius" does indeed cause the borders to be
pleasantly rounded.

Q1: Is there a way I can change my code, and still have the
rounded borders (in browsers that support it) AND have the
CSS validate? (E.g, should I be using a different DOCTYPE
or a different validation service, or can the above
validator take an "allow moz" parameter somehow?)


Q2: As for the "pseudo-element ... can't appear here"
errors, my CSS is [reduced for posting]

::-moz-selection {background: #AF0078 }
::selection {background: #AF0078 }
code::-moz-selection { background: #333333 }
code::selection { background: #333333 }

Are any of these considered correct for mozilla-derived
browsers --and how can I get such to validate?

--Jonathan LF King Mathematics dept, Univ. of Florida