Taginfo has as its goal to find and collect all useful knowledge about OSM tags and make it accessible. But taginfo can’t do everything. That’s why it has always linked to tools that “do something with OSM tags”, the most popular one is probably Overpass Turbo.

About once a year I set aside a week to work on taginfo, one of my many projects that doesn’t get enough attention. And inevitably once I get started there are so many things I want to do that it takes two weeks instead of the originally allotted week. So this time I thought I plan with the two weeks from the start. You probably know where this goes: I spend more like three or four weeks on taginfo…

10 years ago I started the taginfo project. To celebrate this I am introducing some new features!

An international project like OpenStreetMap needs localized documentation. Ideally everybody can use OSM and contribute to OSM knowing only their own language. Of course we are far away from that goal and will probably never fully reach it, but it is worth the effort to try to get there. Taginfo did an important step into the right direction in the last weeks.

I am busy preparing for two events: Only two days now until the State of the Map 2016 in Brussels, where I’ll be giving a talk about taginfo. On Sunday I’ll be hosting an Area Workshop where we want to talk about the effort to fix broken and inefficiently tagged (multi)polygons in OSM. I’ll be around for (part of) the hack day, too.

The most requested features of taginfo is a view showing historical use of tags. I never had the time to add this, but fortunately there is now a solution: Martin Raifer created a service that shows the history of tags in nice graphs. You can see it at taghistory.raifer.tech. Some more background in a diary entry from Martin. Matthijs Melissen has already used this to find some interesting statistics.

About two years ago I introduced the taginfo “projects” feature: A way to connect taginfo with all the uses of OSM tags out there, to editors, special maps, routing services etc. By now we have about 50 projects that have published a project file describing their tag use. This data gets integrated into taginfo and helps mappers and users of OSM data to see who actually uses which tags. Today I have released some changes to taginfo that integrate this information even better.

Matias Dahl has looked at historic OSM data and done some analysis on changing use of the amenity tag including some pretty cool graphs. Nice work and potentially very useful. And he used node-osmium for it. Now, how do we get something like this into a continuously updated service, maybe even into taginfo?

The recent London OSM hack weekend gave me the incentive to work on taginfo once more and we got quite a few things done on the weekend and the days after. Taginfo now works better on mobile, is faster and we have a very cool tag list feature for the wiki. Lets look at these in turn…

Last week I gave a talk about taginfo at the FOSSGIS 2015 conference. Thanks to the amazing video team all talks from the conference are available online in great quality. As always you can find my talk on my Talks page.

I just added a few features to taginfo: There is a new “Similar” tab on all key pages, see for instance all keys similar to the “highway” key. This makes it easy to find related keys and typos. The new Similar keys report shows keys that are commonly used together with similar keys that are rarely used. Often, but not always, the rare keys are just misspellings.

The next annual FOSSGIS conference on Open Source geographic information systems and OpenStreetMap will be held in Münster, Germany, from March 11th to 13th. I’ll be giving a talk there about taginfo.

Taginfo has the “mission” of aggregating all available information about OSM tag usage and present it to the users. The main sources of information are the OSM database and the documentation in the OSM wiki. But there are many more sources of information to be tapped. Everybody who creates a map, or writes presets for an editor, everybody writing a data export program or a routing application has to decide which tags to use in what way. All this is useful information, but it is hard to come by. Everybody uses different programming languages and different config file formats. And all this “stuff” is spread out over many software repositories and web sites.

I spent a few days working on taginfo again. I fixed some bugs and refactored code here and there and added a heap of new features.

In October 2010 I introduced taginfo. Since then I have updated it occasionally and added new functions. And over time it has become part of the “OSM landscape”.

The Map Features wiki page is one of the oldest pages on the OSM wiki and it has been getting larger and larger over time. And more and more wiki templates are used to create it and its language variants. Very similar tables can also be found on many “Key:*” pages on the wiki to list the tags used with this key.

It has been nearly a year since I did some serious work on taginfo. Taginfo works well, but there has been and still is a backlog of todo items. And I get new ideas on how to improve it all the time. So I spent the first days of the new year doing some work on it. A lot of this work has been “behind the scenes”, improving code here or there, so there isn’t actually that much to see. (If you are taking a look remember that you might have to clear your browser cache for all the goodies to show up properly.) But here are the larger improvements:

The Karlsruhe Hacking Weekend is in full swing. About 15 people are sitting around, munching apples, pizza and Gummi Bears and talking about things “somebody” should do “someday”. And we do some actual work, too. I fixed a few bugs in Taginfo, Sven and others are working on updating the German map style. Some people are talking about obscure Mapnik config options. No idea what the other people are doing.

The organisers of the State of the Map Europe have published the programme and it looks very interesting. I will give a talk about Taginfo and a talk about Osmium, the two projects I currently spend my free time on.

Yesterday I gave a talk about Taginfo at the FOSSGIS2011 conference. The talk is in German, you can download a video (570 MB MP4). Many thanks to the volunteers who created the awesome videos of all the OSM talks at FOSSGIS!

Taginfo always had an API so everybody can access all the juicy data in its database through simple HTTP queries. But that API was never used by anyone (as far as I can tell from a quick look at the log files). One reason was probably that I didn’t document the API.

In the past week two people contacted me independently who are working on Taginfo sites with local information for Ireland and Brazil. This prompted me to work on Taginfo again. Taginfo was never intended to be run on more than one web site, but it makes sense for other people to use it, too. So I incorporated some stuff that makes it easier to do that. Taginfo now has a new icon in the top left corner that can be changed for each instance, when you click on it you get some local information. Taginfo sites can add their address to the wiki.

The OpenStreetMap project gets bigger every day. More people edit the data which leads to more data in the database and this to more people using the data. And with the growing database it gets harder and harder to see whats in there. Gone are the days when the common mapper would need to know maybe a dozen different tag keys, each with just a handful of typical values. Today people tag parking spaces and public transport, power lines and penguin pools in their local zoo. Some people are valiantly trying to keep up by documenting tags in the wiki, but sometimes that seems to be a lost cause. There are only about 550 wiki pages describing a key, but there are about 20,000 different keys in the database (about one third only used once, many will by typos) not to mention the 50 Million different tags. What are all these tags? How are they used and by whom? The endless discussions on the mailing lists about what tags to use are partly because the world is complex and fitting everything in our tagging model is not easy, but they are also in part a symptom of this confusing situation.