What is national sovereignty?

Hi everyone. I come from VietNam !
National sovereignty on OpenStreetMap is currently a topic of interest, especially as there have been changes observed in the information regarding the territorial regions of the Paracel and Spratly Islands on the map. The accuracy and transparency of the data are crucial to ensure that people have correct information and avoid misunderstandings.

I would like to propose a discussion on this matter, sharing that, based on the information I have, the Paracel and Spratly Islands are territories under the sovereignty of Vietnam. I have researched from [Geofabrik Download Server] and would like others to share their opinions and knowledge on this issue.

I hope that this discussion will bring about a deeper understanding, and together, we can achieve accurate information and a multi-faceted reflection of national sovereignty on OpenStreetMap. Thank you for everyone’s contributions and opinions!


Hello and welcome! Mapping borders is often very tricky and complicated topic.

Are you familiar with Disputed territories - OpenStreetMap Wiki page and documentation there? If no, I would encourage to read it.

(for this specific case I have not investigated what is going on - but this page was not mentioned and is quite relevant and may answer your question)


The Paracel Islands are listed in the examples on that page, with a link to Wikipedia: Paracel Islands, which states, in part, the following:

The ownership of the islands remains hotly contested. The People’s Republic of China (PRC) on Mainland China, Vietnam, and the Republic of China (ROC) on Taiwan all claim de jure sovereignty, although the PRC has had de facto control of the archipelago since the Battle of the Paracel Islands in January 1974.

About the Spratly Islands, Wikipedia: Spratly Islands offers much information about conflicting claims, including a table that lists 18 islands, and which country currently occupies each, so there is much to sort out there.

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I edited this page a bit adding Spratly Islands entry and adding note how some cases are mapped right now.

Additional note: you can edit/process osm data when using it.

I know about India focused map based on OpenStreetMap but showing borders as claimed by Indian government. Which are distinct from actually controlled area and from OpenStreetMap border data.

The OSMF policy on disputed territories is here. Unfortunately much of the wiki page linked earlier seems not to reflect a lot of the actual discussion that has gone on in OSM to decide how best to represent various places (the first three entries I read were basically “wrong”).

However, with all of these issues, the best place to start is with a discussion, you did absolutely the right thing by asking here.

Full disclosure - I’m part of OSM’s Data Working Group, and Mateusz for info is on the board.

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Can you let me know (here, via PM or via just editing wiki) what is wrong with them?

Or is there maybe a better place to check for this info?

(I am using this page to check what is going when someone is sending emails about bad borders, and I do not really see anything incorrect in the Africa section so I would be glad to learn what I missed so there is lower risk of sending confused/wrong reply)

Taking Western Sahara as an example, I’d suggest that any wiki page explaining “why things are as they are” should mention:

  • a bit about the history (Spanish withdrawal from Spanish Sahara etc.)
  • the various claims
  • the occupation of most of the territory by Morocco
  • the political opposition to that (Polisario Front and others)
  • the building of the “Moroccan Wall” and the fact that that is visible on imagery available to OSM (select Esri to see most clearly).
  • the discussion of “how best to represent this area in OSM” that took place on the old OSM Boundaries forum. See also my answer to this help question.
  • other oddities like the ISO code etc. See also here for the TLD story (ICANN did not grant the use of that to either competing party).
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So this entry is incomplete but not wrong?

Is there a better documentation of situation available somewhere else?

(I edited some of this entries and tried to avoid making claims about history, especially in conflict where I am either unaware of full complexity or biased - what covers all of them)

Something that doesn’t refer to anything in OSM but instead refers to wikipedia is in a very real sense worse than useless, because it will actively mislead people about why the OSM situation is as it is.

The Western Sahara text seems to date from here, and I’m sure was added in good faith by someone who was aware of the dispute but wasn’t familiar with the discussion that had happened in OSM previously. Unfortunately no-one has updated this section (or many other sections) of this page since first added.

The OSMF policy is deliberately very carefully nuanced and carefully crafted to reflect how OSM handles these situations. Many OSM wiki pages simply reflect the state of mind of the person who last updated that page. The OSMF policy also makes it clear that we’ll try and make it possible for people to make maps that fit in with the world view of various jurisdictions where that doesn’t match the situation on the ground. With a DWG hat on I deal with many “disputed territories” questions and an offer to help them to create the map that they want is often part of the answer.

With regard to the wiki, we have very few good technical authors in OSM, and some of the better ones seem to regard the wiki as a lost cause - there’s no point in improving one wiki page if other people can create a dozen parallel ones saying different things that don’t quite agree with each other.

(getting back to the original question)

As the OSMF document states, mentioned above “The OpenStreetMap community operates under the “on the ground” principle, recording what is actually currently used in a particular area, giving pre­eminence to data collected in­situ. This is generally what is used on our main example map at http://www.openstreetmap.org

This therefore means that administrative borders in the OSM data tend to reflect de facto rather than de jure control. However, the creation of every map that you see made with OSM data (including the ones at https://openstreetmap.org has involved someone deciding what data to include and what not to. Many places around the world have rules on how their part of the world should be shown, and maps designed to be used in those places can show what someone in those places would expect to see.

Some sorts of maps can also be created that show different things to different people (for example, a mobile phone app that can use country code or language to decide what to show).

Is your question prompted by:

  1. Some data in OSM not reflecting de-facto control?
  2. The principle that OSM data reflects de-facto rather than de-jure control?
  3. A particular map that you believe is showing incorrect information?

With regard to (1) people make changes to OSM data all the time, sometimes for political reasons - if there is something that is wrong we’ll try and put it right.
If (2) is the issue I suspect (based on previous discussions) that you’ll have a problem persuading the rest of the OSM community to change.
With regard to (3) obviously wed need more detail about “which map”.

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The OSMF policy on disputed territories is here.

does this cover OpenStreetMap Carto as well? There is this sentence: „ OpenStreetMap is a database. You are free to make maps from our data leaving out or putting in what you need for harmony with your general usage, culture and legal system.“, what about carto?

It’s a map, not OSM data. I use a fork of OSM Carto that shows boundaries differently to OSM Carto. It is not rocket science.

Can you link better documentation page about Western Sahara or this discussion that has taken place but was not linked?

Sadly I am unaware of existence of either.

(I am not going to claim that OSM Wiki is optimal or best possible solution, but it is much better than guessing or not using it at all and I am not aware of any plausible alternatives)

I know, but what about the disputed territories, does the guideline cover the map, is it published by the OSMF?

Please, read the document. It says things like “OpenStreetMap is a database” and " our main example map at http://www.openstreetmap.org" - it explicitly distinguishes between what is in the database and what one particular map chooses to show. That can be a difficult concept to get across to people who are unfamiliar with OSM but familiar with (say) Google Maps.

OSM Carto is just one of (currently) 7 map styles visible at https://www.openstreetmap.org . There are many, many more elsewhere. None of them are directly controlled by OSMF. Beyond attribution, there’s no OSMF policy about what a map based on OSM data must show.

Isn’t that a bit off-topic here? The original question was about the Paracel and Spratly Islands.

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Not only that, but it also contained a link to a third-party Geofabrik page that displays its own custom boundary. If I understand correctly, the highlighted polygon on the map on that page shows the extent of the extract that Geofabrik makes, roughly corresponding to Vietnam, but based on a boundary polygon file they maintain independently of OSM data. In particular, it omits some disputed territory that Vietnam claims as its own.

I’ve annotated my previous answer with links to the old forum and a previous help site answer, as well as lots of specific wikipedia links to parts of the history of the conflict. A web search such as this actually does find links that will get you to the relevant OSM forum and help posts.

OSM Carto is just one of (currently) 7 map styles visible at https://www.openstreetmap.org . There are many, many more elsewhere.

I don’t buy that it is just a style as any other, we tell this story to everybody but it isn’t the reality. The other styles on osm.org are not comparable to OpenStreetMap carto which is the default style on the project frontpage (most visitors do not change this) and unlike the others is rendered and distributed from OpenStreetMap-Foundation paid and controlled servers.

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