www.tspforum.com

On an ACD set, KEY 0 is the ACD IN key, KEY 1 is the NRD key, and KEY 2 is the MSB key. This leaves KEY 3 to contain the private DN.
When a call arrives on the private DN, you have to pick up the handset, and press KEY 3. To avoid pressing KEY 3, program the set as follows:

CLS IRA
LPK 3
LPK works a bit like LHK (Last Hunt KEY), so this range defines which keys are to be handled by picking up the handset.

If you also program
CLS OLA
then the DN key (in this case KEY 3) will be activated when picking up the handset to make an outgoing call.