This involves inserting frames using the dsc and next fields into a container already located in the display space. All frames of a container are linked together in priority sequence using the next field. The dsc field points to the first child frame of a container. Note that this is only a convention and certain frames might decide to manage their contents in different ways. The frame messages are used to manipulate Frames.
Frames also respond to the object message defined in module Objects.
The Frame messages are often broadcast into the display space rather than sending them directly to a frame. This is useful when many frames are to be informed of an event. It is also possible to address a broadcast message to a certain frame. This is called a directed broadcast, because the message is still broadcast, but is intended for a specific target only. The target or destination of a broadcast message is identified by the F field in the FrameMsg.