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.

Any map used in wikipedia should conform with wikipedia's policies of neutrality, reliability and verifiability. Any cultural bias apparent in a map (such as a boundary in dispute or a territory claimed by two entities) should be clearly explained in a neutral fashion. The presence of an object on a map is not sufficient by itself to show notability of a subject. Maps can be used for two purposes in wikipedia articles, as sources or as illustration.

Illustration

When a map is used for illustration, the map should follow the same principles as a photo used for illustration. Editor created maps should be careful to only depict details supported by reliable sources in the article and common information that would appear on any published map relating to the subject. For user created maps based on GIS or satellite images, it is acceptable to use details already present in database used to create the map.

Sources

Great care should be taken when using maps as sources in wikipedia articles. Similar to other types of sources, maps should not be self published sources, and the reliability of the publisher should be considered before use. Maps directly derived from government surveys, GIS data and aerial or satellite images are generally reliable. Maps made by commercial interests for promotion of business may not be reliable. Online maps should be treated the same as web sources, listing the date the source was accessed. Like any other web site, the content can frequently change.

Maps can be used to source specific details about the subject, consistent with the intended purpose of the map. For example, It would be appropriate to use a geographical map to source elevations, common names or relative locations, but not necessarily historical timelines. Maps depicting the historical growth of a city are appropriate for historical information, but may not be accurate in other details, such as geographical names. Road maps may be appropriate to source distances and routes, but not land ownership, etc.

Use of a map to source information beyond the intended use of a map can violate wikipedia's policies, such as no original research, verifiability or reliability. For example, if an object does not appear in the 1950 edition of a map, but does appear in the 1951 and later editions of a map, this does not necessarily prove the year of construction was 1950, as this is using the map in a different manner from its intended purpose. It would be acceptable to say "X first appeared on Y map in 1951". It is not safe to assume by an objects presence or absence alone the date of construction, unless specifically mentioned in the map.

When describing the route of a waterway, mountain range, road, railroad, etc., a single map should not be used the sole source used to provide the description. While a map is useful to source details in a general description section, other types of sources should also be used, if available. For some subjects the only sources available will be maps and it will be necessary to have the entire general description sourced from comparing details from several maps. However, this should be done with great care to avoid inserting original research. If a description only contains details from one map, the reader could save time by just looking at the map to get this information. The author should remember that a good article will describe an object above and beyond what is visible in a map.