Employees of the AJDC Berlin also created reference cards for their deportation index. These can be identified by the stamp at the upper edge of the document. Reference cards made it possible to find married women, in particular, not only by their married name but also by their maiden name. Most reference cards were created to point from a maiden name to a married name. There are others too, however, like the one for Helga Drzevicki, which points to her mother Hedwig Rowald.
The cards were filed in duplicate in the digital archive of the ITS: Since two names were recorded (the maiden name and married name), the same card appears for both names. The reference card for Else Wittkowski, née Lewin, can therefore be found in the Arolsen Archives both under L for Lewin and under W for Wittkowski. In the original index at Yad Vashem, however, the card only appears once.