Tibet. (India used in Nepal - Tibet). 1922. Indian KGV postal stationery envelope 'half anna' green upgraded with India SG 155, 1/2a green tied by Nepal double ring on reverse with oval 'Katmandu' hand-stamp under Gyantse arrival addressed to Tibet with Gyantse arrival on reverse.
The oval Katmandu mark is found on mail that was dispatched to and from the British India Post Office in Katmandu from 1920 - 1937.
H. Garrat-Adams was of the opinion that this may have been a censor mark applied by the Nepalese authorities.