In addition to placing packages you can also "place" entities directly such as bond fingers, wires, vias, traces and metal areas.

Metal

A Metal area represents a conductive design object defined by one or more bounding shapes with positive or negative areas. Metal can be defined like this.

(Metal
 (Name 'M-1')
 (Layer 'TOP')
 (Net 'VSS')
 (Shape)
 (Shape
  (Scratch YES)
 )
 (Node)
)

Trace

A Trace is just like a TraceDef except it resides as a single instance directly in RefSpace.

(Trace
 (Name 'T-1')
 (Layer 'BOTTOM')
 (Net 'GND')
 (Polyline)
 (Node)
)

Wire

In this version of AIF v3.0, a Wire is defined in exactly the same way as a Trace, but only the first and last vertices will be considered for purposes of connection.

(Wire
 (Name 'W-22')
 (Layer 'WIREBOND')
 (Net 'IO-25')
 (Polyline
  -4230.0 6318.0 25.0
  -7128.0 8922.0 25.0
 )
 (Node)
)

Package Trace

A PackageTrace is an instance of a PackageDef TraceDef.

(PackageTrace
 (TraceDef 'T-1')
)