To prevent incorrect session setups to TSO or TSO logon failures, the default resource registration is different for TSO applications than for other applications. Applications are registered to a directory server by default because they are likely to be the object of a search. Because multiple TSO applications can be defined using the same name, registering all TSO applications would cause misleading information to be stored in the directory server. Instead, TSO applications are registered according to the following conditions:

• If the APPL resource name is TSO and the ACBNAME is TSO, the default resource registration for this resource is NO registration.
• If the APPL resource name is tsoxxxxx and the ACBNAME is TSO, the default registration for this resource is CDSERVR (register to the central directory server).
• For the APPL resource names for the TSO address spaces (for example, the names ending in 0001, 0002, and so forth), the default is NO registration.