Single import/mapper value suggestion in raw tag editor

[nrenner]

Description

I came accross the tracktype=grade3-5 value and wondered where that comes from.

The OSM tag history graph (see also Taginfo chronology) looks suspicious [i1].

And indeed, there are two special uses:

• 945 ways added by an import in 2014 with changeset 21660337 for some region in Norway [1]
• 890 ways added since July by a single paid mapper [2], almost all to highway=residential in South Africa (no answer to changeset comment)

The latter and other sporadic edits I checked are all using the iD editor, which has that value in the list of suggestions when using the raw tag editor [i2].

Actual

• A single import or user can push undocumented, undiscussed and unsupported values beyond low-usage suggestion limits in iD
• iD is presenting such a tag value as an equal choice, although not in the wiki and usage fraction still only 0.02% [i3]

Expected

• Tag values with low number of different mappers are excluded.
  TagInfo is unlikely to provide that data though (taginfo#37), additionally providing the fraction of imports then even more so.
• Ideas what iD could do:

1. apply autoSuggestions=false (tracktype) also to raw tag editor and use preset values instead
2. show the in_wiki (e.g. as icon) and fraction (e.g. as little bar like in screenshot [i3]) properties that the TagInfo API provides (tracktype) in the value dropdown list

Screenshots

[i1] OSM tag history graph for tracktype=grade3-5:

[i2] screenshot iD raw tag editor dropdown for tracktype:

[i3] Screenshot TagInfo tracktype values:

Footnotes

[1]

curl -o changeset-21660337.osc https://www.openstreetmap.org/api/0.6/changeset/21660337/download
grep "grade3-5" changeset-21660337.osc | wc -l

[2] https://overpass-turbo.eu/s/1kNX

_{edit: above -> [i3] ref, Footnotes heading; values -> properties}