definition
strict definition
parent connection
The link recording that a structure is part of a larger one, such as a building within a complex.
A parent connection records that one structure belongs to a larger one: a tower inside a complex, or a complex inside a cluster.
The connection is what keeps a group countable. Four towers over a shared podium are five records, one per tower and one for the complex, and the connection stops the towers being counted twice.
One building is one record. A single entry named for several towers is a collective row that belongs split up, with a complex above it and one record for each tower beneath.