The parent information of a created object.

In normal packet data order, there are two ways the parent object can be assigned. The first is an implicit association between a parent object and a child object that are both created at the same time. A player character object, for example, is initialized in the same breath as the objects in his inventory are initialized. A weapon object is constructed with an ammunition object already included within itself. The second is an explicit association between the child and the parent where the parent exists before the child is created. When a new inventory object is produced, it is usually assigned to some other existing object's inventory. That is the relationship to the role of "parent" that this object defines. As such, only its current unique identifier needs to be provided. If the parent can not be found, the child object is not created.

A third form of parent object to child object association involves the impromptu assignment of an existing child to an existing parent. Since no objects are being created, that is unrelated to ObjectCreateMessage. Refer to ObjectAttachMessage, MountVehicleMsg, and MountVehicleCargoMsg.

When associated, the child object is "attached" to the parent object at a specific location called a "slot." "Slots" are internal to the object and are (typically) invisible to the player. Any game object can possess any number of "slots" that serve specific purposes. Player objects have equipment holsters and grid inventory capacity. Weapon objects have magazine feed positions. Vehicle objects have seating for players and trunk inventory capacity.