opt-outs
...that four member states of the European Union have de jure opt-outs and do not participate fully in all common policies?
...that four <a class="mw-redirect" href="./List_of_European_Union_member_states" id="mwCbo" rel="mw:WikiLink" title="List of European Union member states">member states</a> of the <a href="./European_Union" id="mwCbs" rel="mw:WikiLink" title="European Union">European Union</a> have <i id="mwCbw"><a href="./De_jure" id="mwCb0" rel="mw:WikiLink" title="De jure">de jure</a></i> <b id="mwCb4"><a href="./Opt-outs_in_the_European_Union" id="mwCb8" rel="mw:WikiLink" title="Opt-outs in the European Union">opt-outs</a></b> and do not participate fully in all common policies?