AT&T MERLIN LEGEND Release 3.0 System Programming And Maintenance Manual page 51

Using SPM
NOTES:
1. You must assign phantom boards to higher slot numbers than any real
boards you assign. If you assign a phantom board to a lower slot number
than a real board, the control unit does not recognize the real board(s) that
follow the phantom board.
2. If you remove a board but do not replace it, and then perform a board
renumber, the control unit will not recognize any boards that follow the
empty slot. You must reseat all of the boards to fill the empty slot before
you perform the board renumber.
The Inspect function ([PgDn]) lets you see which modules have been assigned
to slots on the control unit. Note that both phantom
display if you use the Inspect function. To see only
you must print the System Information report:
System> More> Print>SysSet-up.
Table 5 shows the type of boards that you can select.
System Programming and Maintenance (SPM) 33
boards and real boards
real board assignments,