A unit is an org-chart node, a tower, an approach room, a shift team, each with a parent unit, any number of sub-units, a primary and secondary Head of Unit, a unit code and its own timezone. Alongside the flat list, an expandable tree view shows the full chain of command at a glance.
A unit can be flagged non-operational, a way to keep an administrative or holding node in the org chart without it being treated as part of live rostering logic. Each unit also carries its own contact details and full postal address, useful for a multi-site or multi-country organisation where every control room has its own official address.