Civil Censorship Study Group

Can any of the members throw light on this censor label? It has never been recorded as used from Calcutta.
What does red cross "Timbre response" imply? Was the sender asking for stamps?

Timbre Réponse means that a postage stamp was enclosed to pay for the message form. The Red Cross accepted reply coupons or postage stamps to pay for their service.

Thanks for the info