External information systems are catalogued.

Organisation must maintain a listing of used data systems and their owners. Owner is responsible for completing the related documentation and possible other security actions directly related to the data system.

Data system documentation must include at least:

• System purpose and linked responsibilities
• System's data location (covered in a separate task)
• System's maintenance and development responsibilities and linked partners (covered in a separate task)
• When necessary system's access roles and authentication methods (covered in a separate task)
• When necessary systems interfaces to other systems (covered in a separate task)

The organization shall maintain a list of data sets contained in the data stores it manages.

The documentation shall include at least the following information:

• Data systems and other means used to process the data sets
• Key categories of data in the data set (and whether it contains personal data)
• Data retention period (discussed in more detail in a separate task)
• Information on archiving / disposal of data (discussed in more detail in a separate task)

The organization maintains documentation of interfaces and other connections between data system and the data transmission methods used in the interfaces.

The documentation concerning the interfaces shall be reviewed regularly and after significant changes to data systems.