Commons:Evidence-based mapping

This essay is a summary of existing policies, guidelines, deletion discussion precedents, conventions and recommendations about using reliable sources as evidence when creating/uploading/updating maps to Commons in order to accurately and verifiably show the data in those maps, and about how to use these maps on Wikipedia, especially English Wikipedia. It aims to help users to make accurate maps on Commons that will be acceptable for usage on (English) Wikipedia, to deal with existing inaccurate and unsourced maps on Commons, and to improve cooperation between users.

Creating evidence-based maps on CommonsEdit


Unlike on English Wikipedia, you can still get away with a lot of unsourced, inaccurate and misleading visual information on Commons, especially in mapping. Wikipedians may unwittingly use these maps in articles, where textual claims are usually subjected to rigorous scrutiny to comply with en:WP:RS. But such fact-checking is rare when it comes to the uploading and storage of maps to Commons, where it's still largely an artistic 'free for all' for self-made work, to put it bluntly. You can't just delete someone else's self-made map because it's misleading; a rather high threshold of inaccuracy needs to be met in order to resort to that measure. Commons deletion policies are heavily focused on preventing copyright infringement (and rightly so), but may have neglected means to fact-check whether (self-made) files that comply with copyright are accurate and sourced. (The essay Commons:Verifiability seems to reflect this state of affairs fairly accurately.)

However, although inaccurate or unsourced maps cannot easily be deleted on Commons, English Wikipedia may reject the use of maps which are not based on evidence, and remove them as a result (see 'Precedents' below), so if you actually want the maps you uploaded to Commons to be accepted on English Wikipedia, you better use reliable sources and cite them. Otherwise, you risk wasting your time on creating maps that cannot be deleted, but cannot be used either.

Dynamic versus staticEdit

A separate issue is that there seems to be no clear policy yet – apart from Commons:Overwriting existing files – on which maps should be dynamic (open to updating) and which are static (a reflection of a state of affairs at a certain point in time; a date, year, century). Even though/if their information will grow more obsolete with the passage of time, that doesn't necessarily make them 'inaccurate' or 'misleading', as static maps can still have historical value. Especially if you wish to make a series of maps about the same subject and show what changed over the course of years in the case of, say, changing legislation or demographics, static maps are what you need. A dynamic map usually best reflects the current state of affairs, while static maps can show what preceded the current state of affairs.


  • It is recommended to list your sources in English in the 'Source' parameter, right behind the {{Own}} tag. Proposed format: in the "Source" parameter, state: "{{Own}}. Sources used in creating this map: [bulletpoint list of sources used per country/region that has been coloured in the map]." The sources themselves do not have to be written in English.
  • It is recommended that the source is referenced using one of the regular reference templates, such as {{Cite book |last= |first= |date= |title= |url= |location= |publisher= |page= |isbn= |accessdate=}} (note that 'access-date' doesn't work on Commons; write 'accessdate'). It is recommended that the country/territory/region that the source applies to is mentioned in bold before the source.
  • The 'Description' parameter is best used for describing what the map shows in multiple languages, not on which data the map is based, otherwise the list of sources will have to be needlessly duplicated in multiple languages.
  • It is recommended that the creator mentions/indicates whether their map is dynamic (indicated by {{Current}} or {{Recent}}) or static in the description and if possible also in the title. This is because static maps may be unintentionally taken
  1. by Wikipedia editors and readers to reflect a current/recent state of affairs (when the data may in fact be from over 10 years ago); and
  2. by Commons editors as open to updating (which could lead to maps being changed while their captions/legends in various Wikipedia articles in various languages may remain the same, potentially confusing and misleading Wikipedia editors and readers).
  • Countries/territories/regions for which you have not found any data (yet) should be left grey and labelled 'No data'. If it is a dynamic map, anyone (including you) can later update the map with additional sources added in the description to fill the lacunae in the data, and eliminate "grey" countries. Just like Wikipedia, Commons is a collective work in progress; a map doesn't have to be 'complete' or 'finished' when you upload it, as long as you provide reliable sources for all the data you do present when uploading (or overwriting) the map.
  • It is recommended to use the .svg (scalable vector graphics) file format for making maps, because it's the best way of correcting and updating images, see Help:SVG.
  • It is recommended to make maps language-neutral – or in fact use no text on the maps at all – because that makes it easier to use maps on all language versions of Wikipedia; only the adjoining legend will have to be translated (by you or other users), which can be done in the 'Description' parameter. This saves a lot of work, especially for other users, because it makes your map usable in all languages simultaneously (even languages you can't write (well) in, but other users can), and any updates or corrections are also automatically enacted in all languages simultaneously. Be aware, however, that legends on the various Wikipedias may have to be updated manually if the usage or function of colours is changed on Commons. If not, readers of those language versions can be confused or misinformed by the outdated legends. To prevent this, it is recommended not to change the usage or function of colours in your map – especially if it's used in multiple language versions (and you can't manually correct the legends in those languages because you don't understand them, and you think that translation machines are too unreliable for the task) – unless you really have to correct something. See also Category:Language-neutral maps.


The tools below may help to deal with inaccurate, misleading or unsourced maps you may run into:

  • Template: {{Inaccurate-map-disputed}} – for any map which appears to be showing inaccurate or misleading information.
  • Template: {{Datasource missing}} – for self-made maps that may or may not be accurate, but do not cite any sources on which they are based that would help verify/falsify their accuracy.
  • Templates to indicate that a map is dynamic, and that updates are encouraged and appreciated:
    • Template: {{Current}} – 'Current' indicates a long-term process and is recommended for most dynamic maps.
    • Template: {{Recent}} – 'Recent' requires great urgency and is meant only for maps about a highly important and (rapidly) unfolding event.
    • Template: {{Update}} – for outdated dynamic maps that require updating in general.
  • Maintenance category: Category:Unidentified maps – for maps which purpose is unclear.
  • Precedent: Commons:Deletion requests/File:Imperio de Romania.jpg – example of a successful deletion of a map that was found 'completely worthless'.
  • Precedent: Commons:Graphics village pump/October 2017 – pseudohistoric maps discussion that led to the deletion of the map above.
  • Policy: Commons:Project scope/Neutral point of view – official policy on Wikimedia Commons regarding maps and other things of national(istic), ethnic, linguistic or religious significance.
  • Policy: Commons:Overwriting existing files – official policy on Wikimedia Commons regarding when and how to overwrite existing files, and when and how not to.
  • Essay: Commons:Disputed territories – essay on mapping disputed territories.
  • Essay: Commons:Verifiability – essay outlining how files such as maps uploaded to Commons, and their descriptions, should be assumed to be accurate, unless there is a reason to doubt the description (in which case the description may be corrected) or a reason to suspect the file is a hoax (in which case it may be nominated for deletion).

Evidence-based mapping examplesEdit

It's important to set the right example for self-made, evidence-based mapping, so here are some examples:

Usage of maps on English WikipediaEdit

The fact-checking of maps that are used on English Wikipedia is still somewhat lacking, but some important precedents and conventions have been set that outline some criteria that maps need to comply to in order to be usable and used on English Wikipedia. Although inaccurate or unsourced maps cannot easily be deleted on Commons, English Wikipedia may reject the use of maps which are not based on evidence, and remove them as a result (as the following precedents show), so if you actually want the maps you uploaded to Commons to be accepted on English Wikipedia, you better use reliable sources and cite them. Otherwise, you risk wasting your time on creating maps that cannot be deleted, but cannot be used either.


  • 28 May 2021 Templates for discussion (zoophilia) precedent: en:Wikipedia:Templates for discussion/Log/2021 May 28#Template:Legality of zoophilia by country or territory
    • Conclusion: maps that are based largely on original research (en:WP:OR) should be removed from English Wikipedia, and any templates which embed such maps should be deleted.
  • 30 July 2021 Templates for discussion (animal sentience) precedent: en:Wikipedia:Templates for discussion/Log/2021 August 16#Template:World laws pertaining to animal sentience
    • Conclusions:
      • A. Maps are a visual representation of data, and data must be sourced (en:WP:UNSOURCED). Therefore, lack of sourcing is a valid rationale for deletion of templates that embed them, and removing such maps from English Wikipedia.
      • B. Maps that synthesise data from multiple sources in order to reach a conclusion not found in any source, or bring together data from multiple sources that are not compatible (e.g. population data in which children were only included in some sources), commit en:WP:SYNTH. Therefore, such maps may be removed from English Wikipedia, and any templates which embed such maps may be deleted.
      • C. Merely bringing together data from multiple compatible sources, without extrapolating one's own conclusions from them, is not prohibited in WP:SYNTH or anywhere else, and so no valid reason for removal of maps or deletion of map-embedding templates from English Wikipedia. Therefore, this is a valid way of making maps on Commons and using them on English Wikipedia.
      • No conclusion was reached about whether sources should be listed in the 'Source' parameter in the map's description page on Commons (as this essay recommends), inside the English Wikipedia article or map-embedding template in the form of references (as some Wikipedians argued), or both.

Policies and conventionsEdit

Apart from the precedents above, as of September 2021, English Wikipedia seems to have no clear rules about the need to cite your sources for maps, let alone where and how.

See alsoEdit