The scope of a channel is the code from which it can be accessed.
The following figure shows the same five interactive programs previously described in "Current channel example, with LINK commands".
The scope of the X channel—the code from which it can be accessed—is programs A, B, and C.
The scope of the Y channel is programs D and E.
Note that, by the time control is returned to program A by program B, the X channel has been modified—it doesn't contain the same set of containers as when it was created by program A.
The following table lists the name and scope of the current channel (if any) of each of the five programs shown in the previous figure.