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Improving the OSM map - Why don't we? [3]

Posted by marczoutendijk on 12 March 2015 in English. Last updated on 23 April 2017.

How useful is a tag that exists only once?

The OSM database is simple: A key and a value for every node you want to store into that database. And because it is a liberal database with no checking at all, you can put anything you like, in it.
Of course we have some rules and guidelines:
Map Features
From that we can learn that amenity=hospital is the preferred way to mark (you guessed it) a hospital on the map. Which is used 122164 times on the map (taginfo)
I think most map users have a clear idea on what exactly is meant by that specific tag combination.
But what about this one:
According to the wiki, man_made is:
A tag for identifying man-made (artificial) structures added to the landscape.
Below you see what this man_made=1417-32 looks like: Can you see what it is?? I don’t!
Looking it up in the wiki for that specific value gives (you guessed it) an empty page. Why does one create a specific value for a key, without explaining to others what it means??

On taginfo you can find 1132 entries (75 screen pages) for man_made with a uniqe (used only once) value. This is the last page of taginfo on the man_made key: And the last entry is “junk”.
I looked that one up again: Of course (you guessed it) there is no wiki page on man_made=junk.
In terms of data storage, those 1132 entries don’t take much room, but why use them in the first place? Could the mapper - at least - not have taken the steps (setting up a wiki on that value) to help other mappers with this obscure value?

So please, mappers. If you create a value for a key that is not yet used anywhere else in the database (and think thrice before doing so), be so kind to the other mappers and explain what you are doing and why you are doing it! And even better: discuss this first on the appropriate forum or talk-list.


Comment from Warin61 on 13 March 2015 at 04:40

I and others have had comments made that discourage participation on OSM talk lists.. Generally I ignore them. Some regard the ‘newbies’ as a disturbance that should go away and learn how to do things without disturbing them. Another advises going and mapping them first before talking to the talk group .. then presenting it. The truth is that these are ‘talk’ groups .. designed for talking.. if some on them cannot tolerate errors, mistakes and lots of talk .. then who should leave? Some have taken the hint and don’t participate in the talk groups for that reason. I think some reside on the talk groups to sabotage them!

I too would encourage others to join the talk groups. The more ideas the better I say on any issue/problem. Then one idea can be selected as to the best resolution.

But as to these singular tags .. I think those are ‘errors’ .. end of a long day etc. Possibly ‘private’ marks made by a local mapper for their own reference. Perhaps a new key of test=* or even junk=* could be used for these local mappers private marks? Never know unless they are asked?

Comment from escada on 13 March 2015 at 07:18

I’ve contacted to creator of the man_made=1417-32 node. Asked what the objects represents, and proposed to improve the tagging together. Hope (s)he understands English.

I’ve met several people that do not know about the existence of the mailing lists. With some luck they find the help website. I wonder how many people don’t know about the community around OSM.

I’ve suggested elsewhere that it would be nice if the editors (iD, JOSM, …) would show a help popup depending on the region you are editing. Each country could then add a short message with the best way to contact other mappers, be it email, forum, Facebook, irc, …

Comment from flieger85 on 13 March 2015 at 09:53

sounds good to me

Comment from ProKesTom on 13 March 2015 at 17:56

This is an official triangular point. It´code is the number 1417-32. Detailed information about this point can be found at the CUZK (Czech State Administration of Land Surveying and Cadastre) website. As its coordinates are very exactly known, it is ideal point for for aligning the BING orthophoto maps to the OSM data, if it is visible (this is the case). Of course, this point don’t need to be displayed on a map, but for drawing map it is very useful. In this case, physicaly it is a special stone and an iron pole with a concrete ring around it to protect it. CUZK in english: The point:

Note: coordinates on CUZK are not in WGS, but JTSK also called as “Křovák”. WIKI:

Comment from ProKesTom on 13 March 2015 at 18:48

Some information about Czech Geodetic Points (there is czech and english version of text) can be also found at Can you recommend me how to better tag these points?

Comment from escada on 13 March 2015 at 22:10

I think they should be mapped as [survey points] (

Comment from jutezak on 16 March 2015 at 20:32

It would be rather useful if at least each country would have some ‘authority’ on tagging. Local language, explain how to tag what. Not everyone has time to participate in mailing lists, especially if only adding points or tracks occasionally.

Comment from aceman444 on 28 March 2015 at 23:04

If it is a triangular point, then it is man_made=survey_point. And the number should be put into “ref”, not into “man_made”.

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