'Every December schools and local governments are confronted with the
question of how to approach the holidays without favoring onereligious
faith over another or making some feel uncomfortable because their
religious background is different from others.

To help negotiate the "December Dilemma," the Anti-Defamation League
(ADL) provides public schools and government institutions nationwide
with materials and information on how to keep public recognition of
the December holidays respectful, welcoming and constitutionally
permissible.'

http://www.adl.org/PresRele/RelChStSep_90/5183_90.htm