You can use an EFS program to tailor messages for several purposes:

• To describe new types of operations
• To describe extended field parameters
• To customize the message data set to your site
• To display statistical information about control statements or EXEC PARM options.

You can control whether to print the control statements returned by an EFS program to the message data set with:

• The LISTX installation option (see Installation defaults)
• The LISTX or NOLISTX operators in the PARM field of the JCL EXEC statement (see Specifying EXEC/DFSPARM PARM options)
• The LIST or NOLIST operators of the OPTION program control statement.