Hong Kong geo reference

The geographic reference number is issued by Hong Kong’s Buildings Department and places a building within the territory’s own reference system. This field holds that number.

It answers where a building stands, not which record describes it. The CSUID is the identifier of the record itself, and the two cannot be substituted for each other.

SKYDB stores the number as the department issues it, because it is a departmental reference rather than a coordinate that could be recomputed. The pinpoint is kept separately as latitude and longitude.