[Tagging] Drain vs ditch

[Markus]

On Fri, 11 Jan 2019 at 21:03, François Lacombe
<fl.infosreseaux at gmail.com> wrote:
>
> Regarding ditch, it regards both useful and waste water.

While true in English usage, waterway=drain apparently was intended
for artificial waterways removing undesirable water:

https://lists.openstreetmap.org/pipermail/tagging/2018-August/038505.html

See here for the whole discussion about 'How to tag small canals?'
from August 2018:

https://lists.openstreetmap.org/pipermail/tagging/2018-August/thread.html#38452

If you want to extend the meaning of waterway=drain to also include
artificial waterways, how do you intend to differentiate them from
waterway=canal?

Regards

Markus