AT&T Merlin II Feature Module 2 System Manual page 99

FIGURE 2-10 The order in which lines and line pools are assigned to digital voice terminals.
Message
By default, the system assigns Main Pool
or Pool Access to the first two line buttons.
If you assign a line or line pool, it appears
on the top button in the second column.
S p e a k e r
MERLIN II System Features
2-93