The SLT extensions are set as Extension. I am assuming that the patients using these phones, dialing an extension number, then hitting 7 which will turn on the digital phone's message light. Problem is, the patient is trying to make an outside call but doesn't know to dial 9. So they start dialing a number, which the first four digits are one of my extension number. Then they must hit 7 (or 8 or9) and it turns on the message light. FB41 are disabled on all these phones.