[Tagging] waterway=derelict_canal

[Paul Norman]

On 8/24/2015 3:35 PM, Andy Townsend wrote:
> That's not so bad in lua, but imagine writing "... and not 
> disused=yes" into every cartocss rule! 

Fortunately, we will not have to do that in OpenStreetMap Carto, as we 
will not be supporting the style of tagging where one tag says what 
something is, then another tag saying it's not really that, but used to 
be, or will be. We do not want to encourage the use of disused=yes, 
abandoned=yes, or similar tags.