36 CFR § 1237.24
What are special considerations for storage and maintenance of aerial photographic records?
November 4, 2020
(a) Mark each aerial film container with a unique identification code to facilitate identification and filing.
(b) Mark aerial film indexes with the unique aerial film identification codes or container codes for the aerial film that they index. Also, file and mark the aerial indexes in such a way that they can easily be retrieved by area covered.