> I was thinking more about why Good question - e.g. why isn't a phone number like an email address. My guess is that it functions as an anchor - not to help

> I was thinking more about why Good question - e.g. why isn't a phone number like an email address. My guess is that it functions as an anchor - not to help motion, but to guarantee immobility. Like a physical address, the inconvenience of changing makes for fewer changes. A low-pass filter, for system stability, if you want to look at it that way.