The interpretation section of PDU was officially renamed Photographic Development Unit-Interpretation and Intelligence (PDUI) on 12 June 1940 and codenamed MI4 (Military Intelligence, section 4).
The interpretation section of PDU was officially renamed Photographic Development Unit-Interpretation and Intelligence (PDUI) on 12 June 1940. The interpretation section of PDU was codenamed MI4 (Military Intelligence). Military Intelligence was section 4.