Gday I believe the appropriate policy is probably WP COMMONNAME What name do the majority of sources use That said the full name United Nations Confidence Restoration Operation in Croatia may be less ambiguous so changing it to its official name would probably makes sense even if its not used in the majority of sources To be honest as long as there is a reliable source which verifies that its official name included in Croatia then I would support moving it Maybe just pose the question on the talk page and if no one objects in a few days just be bold and move it I hope this helps