We're on v14 now, but looking at v15. Our current extensions are 3 digits and we're adding extensions into rooms and would like to use room numbers. In one building, we have two digit room numbers, hence the need for two-digit extensions or extensions with leading zero. Is it possible to use a leading zero in v15 or make v14 see this. Our vendor tried adding an extension with leading zero, but it didn't work. He has not messed with v15 yet. I just thought I'd do some checking on my own and see. I was also told that we can only use one format for extensions. Three-digit, for example. I assume that is still correct?