○,A 24,Trieste B. Airmail, the value of 5 Din in dark brown colour originally used for Zone B issue but without overprint (!!!) Not recorded in literature. Stamp is cancelled with poorly legible Yugoslav postmark showing the year '1961'. Probably a one or more (?) sheets intended for STT VUJNA overprinting remained in the warehouse and somehow came into circulation on one of Yugoslav post offices. An interesting curiosity.