[Tagging] Not mapping personal preferences and details

[Tom Pfeifer]

In the wake of the discussion about the methods used to push the "motorcycle_friendly" tag, I found 
that the tag
  "proprietor:motorcyclist=yes/no Whether the proprietor rides himself (and therefore got expertise)"
being described [1], and used 12x in the database.

In my understanding, we would not map the personal preferences and hobbies of individuals.
Also, OSM is not a vehicle registration database.
And I am not even talking about verifiability.

Thus for this case I propose to remove both the description as well as the occurrences in the database.

In general, I wonder if guidelines about not mapping personal details are documented somewhere?
I found "Privacy Policy" [2] which about the privacy of the OSM user, not database details.
I found a German forum discussion [3] about mapping private garden details.
I remember previous discussions about not mapping everybody's grave and not mapping private TVs.

Should we write a section in "Good Practice" [4]?

[1] https://wiki.openstreetmap.org/wiki/Key:motorcycle_friendly
[2] https://wiki.openstreetmap.org/wiki/Privacy_Policy
[3] https://forum.openstreetmap.org/viewtopic.php?id=54712
[4] https://wiki.openstreetmap.org/wiki/Good_practice