Every film gets a unique number, which is composed of three pairs of digits.
The first two digits indicate the year and the second pair shows the month of the film s production. The last two digits compose a consecutive number. This allows us, to give also different films, that were flown at the same day, a unique number. In practice, two methods of archiving have proved to be useful. Vertical photographs are stored film by film in a chronological order, while oblique ones are split up and stored according to the depicted archaeological sites.