A method of operating a portable navigation device or navigation system is described, together, with a computer program and a PND and navigation system. The method includes the steps of providing for a specific premises, location or location range, being identifiable with reference to map data locally stored in the device or system and optionally being or including the current location, can be at least temporarily stored in memory. The method also includes the presenting to the user at least one user-selectable option by means of which qualitative information pertaining to the premises, location or range can be entered locally in the device or system, the selection of the option resulting in the immediate or subsequent recordal and storage of both the qualitative information and an association thereof with the identified premises, location or range.