User DDIC is a user with special privileges in installation, software logistics, and the ABAP Dictionary. The user master record is created in clients 000 and 001 when you install your R/3 System.

You should secure the DDIC user against misuse by changing DDIC’s initial password 19920706 in clients 000 and 001.

User DDIC is required for certain installation and setup tasks in the system, so you should not delete it.