Good question Sam!
With regards to telephone numbers, when I worked on The Scotsman newspaper there was "outrage" when the new switchboard came in and we got a whole new range of phone numbers, and....
Out went the 225 part of the number (i.e. 0131 225 xxxx), since it referred to the old CALedonian exchange.
The same principle went for the area codes like Dartford 01322 (01 DA 2), and Inverness 01463 (01 IN 3).
And main roads are numbered clockwise from London and Edinburgh.
And in aviation - to get back on topic! - danger areas etc are number by the second part of their northing. So at 53N an area would be D3xx and at 54N it would be in the D4xx sequence.
So it would be fun to know if there was such a system for squawks!
ps. To answer the "who cares" argument: Maybe useful if there were two numbers in there whose letters match the station using them?
pps. Why my interest? I use words to generate my PINs!