Changed by DDIC & SAP*
What do those mean? Thank-You.
Ivan Femia replied
SAP* - Clients 000 and 001 include the default super user ID SAP. The SAP user id comes pre-installed in SAP. It is for this reason that it does not need a master record. When a SAP installation team is installing SAP, a user master record is defined for SAP. One small detail which needs to be looked at is in case SAP user master record is deleted, the user can use the password SAP* PASS. SAP bypasses all authorization checks when user logs on again using SAP*.
DDIC - DDIC user id is used to maintain the ABAP/4 dictionary. At the time of SAP R/3 installation DDIC is created automatically in clients 000 and 001. Since, it is a critical user id which can access R/3 during the new installation, it should be handled carefully. Password for DDIC user id should be changed immideately. However, this user id should never be deleted, since same can be used for installation and setup.