Core validator: "uncommon short key" is a correct, "de facto" key ("to" and "from")

[AnkEric]

JOSM validation, Warning: "uncommon short key".

Which key was meant? Only "Pont Akersloot (4 nodes)" is specified.
But after deleting [to=Zuidschermer;Akersloot] is was resolved.
So "to" is an "uncommon short key". So I was tempted to delete this key (also because IMO "to" and "from" for 70 meters of [route=ferry] is rather needless).

But this is not an "uncommon short key":
​https://wiki.openstreetmap.org/wiki/Key:to
​https://wiki.openstreetmap.org/wiki/Key:from
These are WIKI documented tags having Status: "de facto". Yes, "short", but not "uncommon".

So - IMO - JOSM validation should not warn.