To customize VTAM® messages, you only need to code the message or the part of the message you wish to redefine. VTAM will use the user-defined supplementary USS message table in conjunction with the IBM-supplied default USS tables to locate the complete message definition. Several USS tables might be searched before locating a complete message definition. The tables are searched in a specific order (see Order of USS table use).
For more information on coding VTAM messages in a USS table, see Customizing messages.