If you have two or more programs that issue MVS™ system and subsystem commands during a console session and the programs will run simultaneously in a user's TSO/E address space, the programs must use CART values to ensure they retrieve messages intended only for their program. If two programs that use the CONSOLE command's services coexist in one TSO/E address space, you should be aware of the following:

• You should issue all MVS system and subsystem commands with a CART.
• Use the first 4 bytes of the CART as an application identifier. Installations should establish standards so that each program uses an identifier that identifies the program. Whenever the program uses a CART, the CART should begin with the four byte identifier.
• You should not display solicited messages at the terminal. Each application should use GETMSG to explicitly retrieve solicited messages intended for that application.
• You cannot selectively retrieve unsolicited messages. You can have unsolicited messages displayed or you can have one application retrieve all unsolicited messages using GETMSG.
• When you use GETMSG to retrieve a solicited message, you can use the mask argument with the cart argument as follows. Use a MASK of ‘FFFFFFFF00000000’X. The CART should contain the application identifier as the first four bytes. For more information about using a MASK, see GETMSG.