A Package is an instance of a PackageDef. The PackageDef can be transformed but the relative positions of the objects in the PackageDef remain the same. A Package must still maintain a list of PackagePins, PackageBuffers and PackageTraces however, since properties like Net may vary from Package to Package for the same object. (E.g. Two identical ICs, DIE-A and DIE-B may connect their Pin 1 to different objects and they may even be on different nets.) Here is what a typical Package insertion might look like.

(Package
 (Name 'D1')
 (PackageDef 'DIE')
 (Layer 'TOP')
 (Location -2000.0 1000.0)
 (Rotation 5.0)
 (PackagePin)
 (PackageBuffer)
 (PackageTrace)
)

PackagePin

The PackagePin is to the PinDef what the Package is to the PackageDef. The only extra information it contains is what Net it belongs to and what other design objects it connects to. Here is an example.

(PackagePin
 (PinDef '27')
 (Net 'NC')
 (Node)
)

When connecting to a PackagePin, the Node data would be of the form:

 <PackageName>.<PinDef Name>

E.g. (Node (PackagePin 'D1.12'))

Package Buffer

A PackageBuffer is an instance of a PackageDef Buffer.

(PackageBuffer
 (Buffer 'B-1')
)

Package Trace

A PackageTrace is an instance of a PackageDef TraceDef.

(PackageTrace
 (TraceDef 'T-1')
)