Many of the abbreviations on the cards can no longer be easily deciphered today. Sometimes it can help to look for other documents about a person in the Arolsen Archives which might provide clues or explanations. For example, comparing these cards shows that the numbers are the same for all members of a family. However, it is not clear what the red “A,” the number 031119 or the “GI” mean. If you know anything about this, please send your feedback to eguide@arolsen-archives.org.