validator corrects "elevation" to "layer"

[malenki]

Cleaning some duplicate natural=peak today I discovered that the validator criticises the tag
elevation=* as invalid and offers to correct the affected objects.
The correction is, that "elevation" gets changed to "layer".

I propose to change "elevation" to "ele" for automatic corrections or – if "elevation=*" is ambiguous – to disable the correction button for this error.

[Don-vip]

In 6760/josm:

fix #9609 - tagchecker: handling of elevation tag:

• do not replace by layer
• remove elevation=0
• do nothing for other values

[aceman]

Why is elevation=0 removed? Yes, it means "sea level", but there are places in the world where this is true on "dry land" (think e.g. Dead Sea area). An object without any "elevation" tag means elevation unknown, not "0". That is a difference to "layer", where unset defaults to "0", not unknown.

And it seems "elevation" is the wrong key, it should be "ele" per the wiki. So where is that suggestion done in the code?

[Don-vip]

Look for the data yourself:

http://www.overpass-api.de/api/xapi?*[elevation=0][@meta]

This tag is not used to indicate sea level but seems to be used for layer=0. It is ambiguous with positive values where we do not know if it's ele or layer, but I don't care about writing a test for it, it is not used enough (see taginfo).