so you are telling me that since I was asking about the 124i phone system, and now I am asking about a new system, that must mean that I wasn't able to fix a 12 year old system? and after paying the vendor who was also not able to fix it that it was all me? I wouldn't want you to answer for me when you say "shall we assume"

I have been RTFM, I was just asking for some ideas of what it might be called. I didn't say that extension 16 didn't work I asked about why the labeling would go from 15 to 18