Because an XPAC database is hierarchical, each record has relationships with other records in the database. These relationships are normally represented with tree diagrams and are described with traditional family naming conventions such as parent, sibling and child. The following diagram shows the names of the records that are closely related to the reference record, which is coloured red.

The record on level 0 (called Deposit) which represents the entire deposit is referred to as the root of the tree and contains the accumulated data from all the records below it. The other upper level records in the database also contain accumulated data from all the records below them and they are called the roots of the sub-trees beneath them. This is explained in the diagram below.