[Tagging] 'Unknown' value.

[marc marc]

Hello,

 > wheelchair=unknown mostly in Iraq and Saudi Arabia (also from older 
imports)

Many months before this thread, talk for an automated edit was started 
to cleanup 15k+ objets with this value (most due to a wheelmap bug and 
bad undocumented import, but not only).
As the wiki said, for wheelchair, without any tag, the status is already 
unknown and it's requested on the wiki to NOT add unkwnown value.
the discussion was made on the 8 most affected or adapted places,
no one objected or expressed any use for this (wheelchair access) key.
which is why the cleaning was done.
I was also advised to do the cleaning for the remain objets worlwide 
because some countries had less than 50 objects concerned and it 
therefore makes no sense to continue one announcement per country.
We also talk it in this thread, nobody found a usecase for 
wheelchair=unknown.

SomeonElse write me today because since access=unknown could have a 
hidden meaning (= for access key, the mapper doesn't know if access is 
allowed and wants to make it known that it's complicated), he finds that 
this cleaning should be reverteded, at least for cases that don't fit in 
the cases previously listed in the discussions (application bug, import 
of bad qualities).
It is important to specify that the wiki clearly specifies the criteria 
to have wheelchair=yes limited or no.
A state unknown to someone therefore just means that the person who made 
the addition didn't bother to look at the criteria or didn't take them 
into account or found an ambiguity on the wiki that it would be helpful 
to talk about.

So my question is:
Should you modify the wiki to say that if you don't know if a place is 
accessible for a wheelchair user, you still need to add an unknown tag ? 
if the situation is really ambiguous, isn't wheelchair:description 
enough ? or note ? or fixme ? or no wheelchair tag at all, another 
mapper 'll check it next time.
Or should all applications take this unknown value into account? I think 
for example of the multiple tools that highlight the missing values for 
a given subject and which would therefore need to consider unknown as 
equivalent to absent. but also "maybe" "idontknown" "idontcare" values 
or any invention of this kind whose interest I hardly understand.

My opinion is obviously leaning to add useful tags. so if someone is 
unable to tag wheelchair status for a POI, don't add any wheelchair tag 
or adding WHY in wheelchair:description or note seems more suitable to 
me than inventing new unused value that provides no explanation for the 
problem. and therefore are unusable except for the mapper that create it

[1] 
https://wiki.openstreetmap.org/wiki/Automated_edits/marc_marc#purge_related_to_wheelchair.3Dunknown
[2] https://wiki.openstreetmap.org/wiki/Key:toilets:wheelchair

Regards,
Marc