If I disagree with an internal CERN policy, is it acceptable for me to express my disagreement?

You can express your views when contributing to CERN policymaking, but once policies have been adopted you should refrain from publically expressing views that undermine the policy. If you have concerns about a current policy, it is best to address them through your hierarchy, the Human Resources Department or the Staff Association, a body that has an ongoing responsibility to foster productive staff/management relations and to stimulate dialogue about internal issues.