Numbering scheme

Template:Short descriptionTemplate:Onesource There are many different numbering schemes for assigning nominal numbers to entities. These generally require an agreed set of rules, or a central coordinator. The schemes can be considered to be examples of a primary key of a database management system table, whose table definitions require a database design.

In computability theory, the simplest numbering scheme is the assignment of natural numbers to a set of objects such as functions, rational numbers, graphs, or words in some formal language. A numbering can be used to transfer the idea of computability and related concepts, which are originally defined on the natural numbers using computable functions, to these different types of objects.

A simple extension is to assign cardinal numbers to physical objects according to the choice of some base of reference and of measurement units for counting or measuring these objects within a given precision. In such case, numbering is a kind of classification, i.e. assigning a numeric property to each object of the set to subdivide this set into related subsets forming a partition of the initial set, possibly infinite and not enumeratable using a single natural number for each class of the partition.

In some cases (such as computing, time-telling, and in some countries the numbering of floors in buildings) zero-based numbering is used, where the first entity is assigned "zero" instead of "one".

Other numbering schemes are listed by field below.

Chemistry

• CAS Registry Numbers for chemical compounds
• EC numbers for identifying enzymes
• UN numbers for (classes of) hazardous substances
• E numbers for food additives

Communications

• The E.164 numbering plan for telephone numbers, including:
  • Telephone country codes
  • North American Numbering Plan
  • Numbering plans by country
• The IP address allocation scheme (IANA)
• The DNIC prefixes of X.25 NUAs (Network User Address) assigned by the ITU
• Object identifiers (OID)

Computing

• Line number

Products

• The GS1 numbering scheme, including
  • GTIN for products, which includes the UPC and EAN-13 barcodes
  • ISBN codes for books
  • ISSN codes for periodicals
• Vehicle identification number
• Stock keeping unit (SKU)

People

Identification numbers

• National identification numbers
  • Personal Numeric Code (Romania)
  • Personal identification number (Denmark)
  • Social Security number (United States)
  • Social insurance number (Canada)
  • INSEE number (France)
  • National Insurance number (United Kingdom)
  • Aadhaar (India)
• Personal Public Service Number (Republic of Ireland)
• Tax file number (Australia)
• Unique Master Citizen Number (former Yugoslavia)
• Det Centrale Personregister (Denmark)

Ordinals for names

• Regnal numbers
  • Princes of Reuss
  • Popes' ordinals
• Generational ordinal suffix to names

Topics

• Dewey Decimal Classification and Universal Decimal Classification for books
• West American Digest System legal topic numbering scheme

Geography and transport

• Postal codes
  • ZIP codes
• Geocodes (used also as fine-grained postal codes):
  • Geohash
  • Open Location Code
• Global Location Numbers by GS1
• FIPS place codes
• House numbering schemes
• Floor numbering
• Room number
• See also: Country code; Address (geography).

Vehicles

• Vehicle registration plates
• British Carriage and Wagon Numbering and Classification
• British Rail locomotive and multiple unit numbering and classification
• UIC classification of goods wagons

Roads

Road numbering schemes

• Arlington County, Virginia, street-naming system
• China road numbering
• Great Britain road numbering scheme
• European route by UNECE
• Numbered highways in the United States
• Edmonton, Alberta#Street layout
• Montreal
• Highways in Australia#Route numbering systems

Others/general

• API well numbers for numbering oil and gas wells in the United States
• Bank card number
• International Bank Account Number
• International Geo Sample Number (IGSN)
• International Statistical Classification of Diseases and Related Health Problems for diseases
• The MAC address allocation scheme for hardware addresses of certain networking products
• National Animal Identification System
• National Pokédex
• The NSAP allocation scheme
• Post office box
• Production code number
• Stamp numbering system
• Wikipedia markup syntax for numbered lists

See also

• naming scheme
• Digital Object Identifier
• Pagination
  • Stephanus pagination for works of Plato
  • Bekker numbers for the works of Aristotle
• Persistent identifier
• Unique identifier
• UUID