Every entity of a package is a box, and every reference between entities is a line from the entity
whose field holds the reference to the entity it points to. The boxes are grouped by subject. Point at
an entity or move to it with the keyboard to highlight its references and see the names of their fields;
click it to open its page. Drag to move the map; zoom with the buttons, by pinching, or with Ctrl or ⌘
and the mouse wheel.
A solid line is a reference through a required field.
A dashed line is an optional reference.
A double arrowhead means the field can point to records of several entities.
tree
A record can sit under another record of the same entity.
self
A record can refer to another record of the same entity.
→ n / ← m: the entity refers to n entities, and m entities refer to it.
Entities by group
The same map as a list: every entity and the entities it refers to.