Required fields should prevent submitting. They do not prevent the
user printing, because a user can print at any time. You cannot
selectively prevent printing at all (and what if a user wanted to
print out a partial form for discussion, evidence, or problem
reporting?) Adobe's programmers have clearly thought in terms of
enabling users, not restricting their experience. Right or wrong.
What you COULD do is have a printable but hidden field which says in
large letters that the form is incomplete, do not accept. Checking
scripts can hide the form from printing when conditions are met.
You could also wait to be notified of printing, and warn the user that
their printout is unacceptable.
Aandi Inston