[Tagging] waterway=derelict_canal

[Christoph Hormann]

It is not the first time this subject (here literally this subject) has 
been discussed:

https://lists.openstreetmap.org/pipermail/tagging/2015-August/thread.html#26101

By the way the wiki page

https://wiki.openstreetmap.org/wiki/Tag:waterway%3Dderelict_canal

is a great demonstration of how dysfunctional the tag documentation on 
the wiki has become - in this case with the attempt to encourage 
improvement of the tag documentation being scuttled by silently 
removing the verifiability template.

-- 
Christoph Hormann
http://www.imagico.de/