|Used for reference numbers or codes. Common for roads, highway exits, routes, etc.|
|Used on these elements|
|Status: De facto|
|Tools for this tag|
"ref" stands for "reference" and is used for reference numbers or codes. Common for roads, highway exits, routes, etc.
For cycle routes
There is a wide use of ref:*=*. Main values are listed above :
|key||used on||description||see||taginfo (13 June 2013)|
|ref:INSEE=*||admin_level=*||INSEE code of the French communes||Key:ref:INSEE||74,178|
|ref:isil=*||library||International Standard Identifier for Libraries||Key:ref:isil||1,062|
|ref:lmi=*||heritage||id in Lista monumentelor istorice||Proposed features/heritage||0|
|ref:mhs=*||heritage||id in the French database Mérimée of historic monuments||Proposed features/heritage||4,764|
|ref:nid=*||heritage||id in Narodowy Instytut Dziedzictwa historic monuments||Proposed features/heritage||1,533|
|ref:nrhp=*||heritage||identifiers for (United States) National Register of Historic Places (NRHP) records 22||NRHP advanced search||24|
|ref:rce=*||heritage||id in Rijksdienst voor het Cultureel Erfgoed||Proposed features/heritage||8|
|ref:sandre=*||river||ref of the French Sandre agency||WikiProject France/Cours d'eau||2,336|
|ref:svhl=*||station-keys of Lübecker Stadtverkehr (Germany)||Lübeck/Importe||2,289|
|ref:whc=*||heritage||id of the Unesco World Heritage||Proposed features/heritage||226|
|ref:ERDF:gdo=*||line or substation||Id of French power distribution facilities||Key:ref:ERDF:gdo||0|
|ref:FR:42C=*||central_office||Id of French telephone copper local loops facilities||Key:ref:FR:42C||0|
|ref:bag=*||Id of Dutch buildings||BAGimport||0|
User defined values
Any valid syntax value
Examples on relations
States and provinces are often tagged with a postal abbreviation in ref. For example:
- ref=CA The state of California (type=boundary, admin_level=4, name=California - currently relation 165475)
On road routes, the ref is a bare number, relying on network=* to convey information about the road network:
Bus routes use ref to label the bus route. For example:
- ref=23 Bus route 23. (type=route, route=bus, name=Shanklin>Newchurch>Newport - currently relation 312207)
Examples on ways
There are no global standards as to whether the refs include spaces, hyphens or other characters. At least when nationally consistent, tag what's on the ground. Some countries use spaces on the signs, others don't. In some countries the usage on the signs varies and guidelines are under discussion.
- ref=A 1 Default reference (German and French references with a space; e.g., A 1)
- int_ref=E 15 Internationally referenced as
- nat_ref=A 1 Nationally referenced as (German and French references with a space; e.g., A 1)
- reg_ref=A 1 Regionally referenced as (German and French references with a space; e.g., A 1)
- ncn_ref=54 The number reference for a National Cycle Network. See Cycle_routes
- ref=A 3;A 7 Default for more than one reference (German and French references with a space; e.g., A 1)
Examples on nodes
- ref=23 US Highway exits are often just a number
- ref=23B Sometimes exits have been split into A and B exits.
ref is sometimes used on bus stops:
ref is sometimes used to label an entrance into a large parking area. For example a shopping mall may have entrances A - L:
- ref:svhl=* - station-keys of Lübecker Stadtverkehr (Germany) - details look at Lübeck/Importe
- ref:luebeck=* - internal reference for objects the area of Lübeck
- ref:bufa=* - 4-digit key of the local German tax and revenue offices (Bundesfinanzamtnummer)
- ref:vatin=CC12345678 - VAT identification number of companies, use CountryCode (e.g. IT for Italy) and the number
- official_ref=* - Used in cases where the official administrative reference for a road (or other feature) is not identical with the road signs (or other feature ref), e.g. because they are old, or because the administration doesn't have the money to change the signs.
- For highways shared by more than one route see Relations/Routes or Faq#What shall I do for roads that have multiple values for a tag?. Relations seem to be the preferred method for tagging this.
- If more than one reference is given, you are recommended to separate them with a semicolon and without a space character, because this is the widely established syntax in Germany and maybe other countries. But note, this syntax is being heavily discussed in Germany. A better approach might be to have a namespace and add the entity that has issued the ref, e.g. ref:foo=x ref:bar=y.
- Do not confuse this issue with the space that is present in some countries between the letter and the number in a reference itself.
- When a road has no number, leave this key unused; this makes sure that routing programs do not try to describe the road by a number.