Baltimore, MD. For every Social Security Account Number issued an "emploee master card" is made in the Social Security Board Records Office. Identifying data, given on the application blank , Form SC-5[?], is transferred to this master card in the form of up-ended quadrangular holes, punched by key punch machines, which have a key card like a typewriter. Each key struck by an operator causes a [...] to be punched into the card. The position of a hole determines the letter or number other machines will reproduce from the master card. From this master card is made an acturial card, to be used later in statistical purposes. The master card also is used in other machines which sort them numerically, according to account numbers alphabetically according to the name code, translate the holes into numbers and letters, and print the data on individual ledger sheets, indexes, registry of accounts, and other uses. It is kept as a permanent record. The photograph above shows at work a part of the key machine section, where master cards are punched.