When a password is added for a data set, an entry is created in the PASSWORD data set with the specified data set name, password name, protection mode of the password (read/write or read only), and the optional 77 characters of user-supplied data. The access counter in the entry is set to zero.

The control password for a data set must always be specified to add, replace, or delete secondary passwords. The control password should not be specified, however, to list information from a secondary password entry.

Secondary passwords can be assigned to a data set to restrict some users to reading the data set or to record the number of times certain users access the data set. The access counter in each password entry provides a count of the number of times the password was used to successfully open the data set.

If a control password for an online DASD data set is added, the protection status of the data set (read/write or read-without-password) is set in the DSCB.