Meaning of the caption at the bottom of the photo: first set of numbers is the photograph's item number. First acronym (three or more letters) designates the air base (operational base). Second set of numbers are the dates the aircraft took off and landed (format: Day aircraft took off/Day aircraft landed.Month.Year). Second acronym (two or more letters) is unknown (e.g., NT could mean nighttime). Third set of numbers (one digit) is unknown (e.g., 8 could mean the focal length of the camera used to take the picture). Fourth set of numbers (five digits) is the altitude. Fifth set of numbers (three digits) is the aircraft heading, the direction in which the longitudinal axis of an aircraft is pointed, expressed in degrees from North. Sixth set of numbers (fourth digit and fraction) is the time of the photograph (probably the British time zone). First series of text is the bombing target (the location) (e.g., Le Bourget is a suburb of Paris). Second series of text is unknown (e.g., RAID S). Seventh series of numbers (format: number x number) is the load of bombs carried by the aircraft (e.g., 7 of the 1,000 lb and 6 of the 500 lb). Eight sets of numbers (two digits) are unknown. It could be the interval (in seconds) when the bomb was dropped and the camera took a photograph. Third series of text is the rank and pilot name, e.g., P/O Mitchell, Pilot Officer Mitchell. Last letter is the alphabetic code painted on the side of the aircraft (e.g., T). Last series of numbers (three digits) is the squadron number (e.g., 429).The Red Writing was written on photo by an analyst. Using an earlier daytime photo of the target taken by a reconaissance aircraft, they would identify features on the ground in the photo taken by the bomber. From that, they could draw a line pointing North and determine how many yards and in what direction the bomber was from the intended aiming point. (e.g., 1800 yds 164? NNW from target) These analyzed photos were then individually plotted on a large sheet of paper, and put in a report.
