Abstract: The file contains coded messages sent to and from Bahrain Petroleum Company Limited (BAPCO), forwarded to the Political Agent. For security reasons, the messages were coded and the file also contains their transcriptions, mainly on the subject of oil wells maintenance in Bahrain.Physical description: The foliation is written in pencil, in the top right corner. The numbering begins on the front cover, on number 1, and runs through to 33, 34A, 34B; folios 66-69 are missing, then it carries on until folio 101, which is the last number given on the back cover of the file.