Anthony G. Atkielski;
I've described variable-length addresses in the past. Essentially a
system like that of the telephone network, with addresses that can be
extended as required at either end. Such addressing allows unlimited ad
hoc extensibility at any time without upsetting any routing already in
place.
Unlimited? The limitation on public part is 20 digits.
Ad hoc extension beyond hardware supported length at that time will
fatally hurt performance.
Masataka Ohta