Verizon for one, at least in the US. I know I used e164.arpa for testing purposes, until new management came in and demanded we use the domain we use in produc

Verizon for one, at least in the US. I know I used e164.arpa for testing purposes, until new management came in and demanded we use the domain we use in production for testing (because, well, production, I guess? Keep the configs as the same as much as possible?). Now that I've name names (or a name), how about you? Who uses e164.arpa?