Facts and Figures: The Tattooing Process at Auschwitz

In order to avoid the assignment of excessively high numbers from the general series to the large number of Hungarian Jews arriving in 1944, the SS authorities introduced new sequences of numbers in mid-May 1944. This series, prefaced by the letter A, began with “1” and ended at “20,000.” Once the number 20,000 was reached, a new series beginning with “B” series was introduced. Some 15,000 men received “B” series tattoos. For an unknown reason, the “A” series for women did not stop at 20,000 and continued to 30,000. 
Read More at: http://www.ushmm.org/wlc/en/article.php?ModuleId=10007056