There are many different numbering schemes for assigning numbers to entities. These generally require an agreed set of rules, or a central coordinator.
Numbering schemes include:
The E.164 numbering plan for telephone numbers, including:
... people, 509 households, and 417 families residing in the town. The population density is 129.8/km² (336.2/mi²). There are 519 housing units at an averag ...