You can have SEND store messages for some of your users in individual user logs and use the broadcast data set as the message repository for other users. First, to implement the use of user logs, follow the instructions described in Converting from using the broadcast data set to user logs. To use the broadcast data set for some of your users, write an initialization exit for the SEND, OPERATOR SEND, and LISTBC commands. The initialization exit can change the name of the data set that the command (subcommand) processors use to store and retrieve messages. For more information about the exits, see Writing exits for the SEND, OPERATOR SEND, and LISTBC commands.