Art 43. Upon the outbreak of hostilities, the Parties to the conflict shall communicate to one another the titles and ranks of all the persons mentioned in Article 4 of the present Convention, in order to ensure equality of treatment between prisoners of equivalent rank. Titles and ranks which are subsequently created shall form the subject of similar communications. The Detaining Power shall recognize promotions in rank which have been accorded to prisoners of war and which have been duly notified by the Power on which these prisoners depend.