There are two basic units of inventory in the Pops system. A tract of land and a well. Both have specific geographic coordinates. A title document describes one or more tracts of land. A statement of interest, like a division order, will describe one or more wells either specifically or by inclusion in a land description.

Each well so described is in a specific location and all tracts of land that encompass that location are impacted by its presence.

Leases, which grant ingress and a term of rights, describes land by tracts also. However, the lease may describe a tract of land that extends beyond the boundaries of any given tract described by a title document.

All of this has a vertical aspect as well. There are many layers defined by depth or geological formation. These can exist in the real world above and below each other.