Cover franked with 1937 2½d ultramarine GVI issue (SG 466) tied by LONDON machine cancel dated 2 SEP 1939. Addressed to PORTUGAL with boxed 'RETURN TO SENDER' marking in purple and printed green on white 'RETURNED TO SENDER BY THE CENSOR FOR REASON EXPLAINED IN MEMORANDUM ENCLOSED IN THIS COVER' censor strip at left and black on yellow 'P.C.3.' label attached on front with printed message 'Postal Censorship. The communication returned in this cover constitutes a breach of the Defence Regulations. The writer is warned to be more careful in future. N.B. - The communication will be allowed to proceed if the passage or passages referring to 'Cheque' are omitted, and if it is re-posted to the addressee in the usual way. 'Consult your bank re. export of license permit'. Cover has various other manuscript markings and notations and two punched holes at top.