Wikipedia:Using maps and similar sources in Wikipedia articles

This is an essay. It contains the advice or opinions of one or more Wikipedia contributors. This page is not an encyclopedia article, nor is it one of Wikipedia's policies or guidelines, as it has not been thoroughly vetted by the community. Some essays represent widespread norms; others only represent minority viewpoints.

Shortcut WP:MAPCITE

This page in a nutshell: Maps and line charts used as illustrations follow the same rules as pictures that are used as illustrations Maps and line charts may be used as sources, but the core content policies Verifiability, and No original research still apply. It is not original research to extract information from a map or line chart using standard techniques, particularly if those techniques are common to two or more disciplines. The core content policies of Verifiability, and No original research apply to user-made maps.

Any map or line chart used in Wikipedia should conform with Wikipedia's policies of neutrality, reliability and verifiability. Maps can be used for two purposes in Wikipedia articles, as sources or as illustration. Regardless of the point of using a map in an article, the following points should be kept in mind:

• The presence of an object on a map is not sufficient by itself to show notability of a subject.
• Even maps produced using reliable sources (such as GIS data) can have minor errors as a result of errors in the underlying database, or the cartographer trying to overlay data from two non-linear sources. Minor map errors are common, for that reason any map detail that is key to the article should be confirmed with a separate map from a different publisher. Rarely are map errors notable, even if they have gone uncorrected for decades.
• Many cartographers intentionally introduce minor errors in inconspicuous locations as a form of copyright trap. Likewise, rarely are such introductions notable.
• Many companies publish a yearly edition of a map, and include the year as part of the title (e.g. 2009 Road Atlas). As these have to be drafted in advance, often the cartographer will draw projects under construction as completed, or proposed projects as under construction. This is an effort to increase the shelf life of the map, so as to not be obsolete before the year on the edition name has finished. (e.g. a highway expected to be completed by 2009 may be drawn as complete in the 2009 edition, even though it was still under construction when the map was drafted) This can introduce another source of error in an otherwise reliable map, should a project be cancelled or significantly changed. Such errors can be detected by comparing multiple editions of the same map.
• Any cultural bias apparent in a map should be clearly explained in a neutral fashion. For example, Wikipedia's article about the Falkland Islands sovereignty dispute features side-by-side maps showing the rival naming conventions used by Argentina and the United Kingdom for the named features of the islands, without implying one is correct. In cases where it is not practical or possible to show maps from each POV in a boundary or sovereignty dispute, a caption should explain which details of the map are disputed.
• Editors who use maps should be aware that maps covering large areas almost always have one type of distortion or another, depending on the map projection used. Care should be taken to select a map whose projection is appropriate for the purpose to which it is being put.