Any of the following information may be replaced in a password entry: the password, protection mode (read/write or read only) of the password, and the 77 characters of user data. The protection status of a data set can be changed by replacing the control entry for the data set.

If the control entry of an online DASD data set is replaced, the DSCB is also reset to indicate any change in the protection status of the data set. Therefore, you should ensure that the volume is online when changing the protection status of a DASD data set.