Improvements: charge tags

[jpc-ae]

Please add the charge=* and charge:conditional=* tags to parking since they are highly useful. I haven't checked other tags, but it really belongs in any preset that includes a fee or toll. See: https://wiki.openstreetmap.org/wiki/Key:charge

[simonpoole]

They are even more controversial than opening hours and other tags that are at best only semi-stable properties with very limited usefulness. That said, I might still add entries for them, but as for all structured tags to actually "work" it really needs a parser and dedicated UI.

[jpc-ae]

It's in iD and, at least for street parking (my use case), permanent enough data that many of the signs are yellow with age...

Even if charge:conditional has limited use and may be hard to implement (though fee:conditional is already there), the plain charge:* tag at least should definitely be there, I feel, since it's posted sign data worth mapping and the charge tag has won out at this point for said data.

[jpc-ae]

For reference, here are the relevant tags I've used at this location:

amenity=parking
charge=1 EUR/hour
fee=no
fee:conditional=yes @ (Mo-Sa 10:00-18:00 AND stay > 1 hour)
maxstay:conditional=2 hours @ (Mo-Sa 10:00-18:00)
parking=street_side