An optional part of the mnemonic describes the device providing the soft key. If the module indicator M is present, either a module 0 indicates the button is on the station itself, or the number indicates the button page on which it is found.
If the module indicator M is not present, the button is on the station and not a module.
Legend:
SCBbbMmUx:
SC: speed call
B: feature button
bb: button number (00 to max on station or on extension module)
M: expansion module, when an expansion module is to provide this button
m: module number (1, 2, or 3; optionally, 0 can be used to indicate the actual station)
U: user
x: 1–3 (Abbreviated list 1, 2, or 3)
SCBbbUx:
The absence of the Mm indicates that this is on the station itself and not a n expansion module
SC: speed call
B: feature button
bb: button number (00 to max on station or on extension module)
U: user
x: 1–3 (Abbreviated list 1, 2, or 3)
Mm is omitted because this button is not on a button module.
SCBbbMmCx:
SC: speed call
B: feature button
bb: button number (00 to max on station or on extension module)
M: expansion module, when an expansion module is to provide this button
m: module number (1, 2, or 3; optionally, 0 can be used to indicate the actual station)
C: controller
x: 1–3 (Abbreviated list 1, 2, or 3)
SCBbbCx:
SC: speed call
B: feature button
bb: button number (00 to max on station or on extension module)
C: controller
x: 1–3 (Abbreviated list 1, 2, or 3)
Mm is omitted because this button is not on a button module.
