Database Model (ERD)
Transactions
SPT / when is data saved / how is old data restored ?
Display files
Module structure
Naming conventions
List of important modules
Static data (incl. MDxBUT dev doku, allget dev doku)
Entity/Entity group/Entity address
Party Model
Interfaces (and how to define new interfaces)
Service Order
Templates/Messages/SMH
Logs/Events/Notify/SLG
Sessions
CBS / RNGMOD
Documentation (online help/dokuwiki)