[OSM-talk] Amenity key

[Dave F.]

On 25/10/2010 10:23, Markus Lindholm wrote:
> On 25 October 2010 11:17, M∡rtin Koppenhoefer<dieterdreist at gmail.com>  wrote:
>> 2010/10/25 Dave F.<davefox at madasafish.com>:
>>
>>> Tourism is a tag that shouldn't be used as a primary.
>>>
>>> Primary tags should be used to describe what it is, not whom it *might* be
>>> used by.
>>
>> what about tourism=information with it's several subtags? Seems to fit
>> perfectly IMHO as a primary tag.
> What constitutes a primary tag?

One that is used in to solely describe an entity without any additional 
sub-tags.

Tourism is an activity.
A museum needs a tag to describe it's physicality such as building=*, & 
maybe building:use=*

Museums (& art galleries) are used by many people other than tourists.

To indicate that it might be of interest to tourists a sub key such as 
tourism=yes could be used.

> How should one know which tags are
> considered primary when parsing the OSM database?

That's up to the parser. However putting tourism=art_gallery for example 
gives no indication of what type it is:
Is it indoors or outdoors?
Is it in a building, marquee, greenhouse? etc.

Cheers
Dave F.