Effectively its not a kingdom Therefore the title doesnt vital Visit the eldest son but to the person they Consider is the greatest with the title: brother , son , cousin ... but as an Emirati I believed I could solution your dilemma about sending cards to Royals here in https://benefitofdubairoyalmember46789.suomiblog.com/new-step-by-step-map-for-royal-membership-card-48416894