When you name a file in your personal filing system, you can name it anything you want. A computer system, however, imposes some rules for naming data sets. The rules for naming TSO/E data sets are:

• A data set name consists of one or more parts connected by periods. Each part is called a qualifier.
• Each qualifier must begin with an alphabetic character (A to Z) or the special character @, #, or $.
• The remaining characters in each qualifier can be alphabetic, special, or numeric (0 to 9) characters.
• Each qualifier must be 1 to 8 characters in length.
• The maximum length of a complete data set name before specifying a member name is 44 characters, including the periods.

Some valid TSO/E data set names are:

X
PREFIX.TEST1
DEPT58.IDEAS.FUTURE.APPROVED.#4