Panasonic KX-NS500 Features Manual page 502

5.2.4 Portable Station (PS) Features
PC Programming Manual References
9.35 PBX Configuration—[1-2] Configuration—Portable Station
PT Programming Manual References
[690] PS Registration
[691] PS Termination
[692] Personal Identification Number (PIN) for PS Registration
Feature Guide References
5.5.7 Flexible Numbering/Fixed Numbering
502 Feature Guide