Page 168 of 504 M 3900 description
553-3001-367 Standard 3.00 August 2005
Note: For M3904 and M3905 telephones, One-button feature access
keys for the Callers and Redial lists cannot be programmed on DBA or
KBA modules.
Figure 34
M3904 key positions
553-AAA0668
Key [0,6]
Key [1,7]
Key [2,8]
Key [5,11]
Key [4,10]
Key [3,9]
Key 16
Key [17,20,23]
Key [18,21,24]
Key [19,22,25]