Panasonic KX-TD500 System Reference Manual page 1130

• Deleting the ATLC card will be an error if there is one of the following assign-
ments:
— "Trunk Group (TG1)",
Incoming Mode (Day) is set to "1 (ATT)".
Intercept Routing (Day) is set to "A (ATT)".
— "Doorphone (DPH)",
Doorphone Call Assignment is set to "A (ATT)".
• Deleting the DISA card will be an error if there is one of the following assign-
ments:
— "Trunk Group (TG1)",
Incoming Mode (Day) is set to "4 (DISA)".
Incoming Mode (Night) is set to "4 (DISA)".
• Deleting the HLC, SLC, MSLC, DHLC, ESLC, LCOT, RCOT, PCOT or GCOT card
will be an error if there is the following assignment to the slot to be deleted:
— "Power Failure Tansfer (PFT)"
11-C-4