[Tagging] minus or underscore in attribute values?

[Martin Koppenhoefer]

> Il giorno 23/ago/2014, alle ore 10:42, "Richard Z." <ricoz.osm at gmail.com> ha scritto:
> 
> another mapper metnioned to me that it is unusual to have
> attribute values with a minus, like
>  bridge:structure=cable-stayed


this is a language question. When the word is cable-stayed (one composite word) the tag is also cable-stayed, while for tags made up of 2 distinct words like "foo bar" the space gets replaced by an underscore: foo_bar because formal values (finite lists of predefined values) must not contain spaces.

Another variant is the colon used to create subtags like in historic:civilization 

cheers,
Martin