Indicate that a search result is from TIGER data

[simonpoole]

Is your feature request related to a problem? Please describe.
For a "normal" user the difference between results from TIGER and OSM data are not clear and can be surprising. In particular clicking on the result will select and display the street without any further explanation.

See for example https://www.openstreetmap.org/search?query=16%20Slayton%20Road%20melrose%20Massachusetts.#map=19/42.45596/-71.04467

Describe the solution you'd like

An indication in the results display that this is not a "proper" result from OSM.

[lonvia]

I think we use to return a 'T' type for Tiger house numbers in osm_type but changed that when going to spelled out OSM types. @mtmail do you happen to have a reference to the discussion back then? If I remember correctly the reasoning was that osm_type should not contain surprising values. And that still holds. Putting a new value in there is a sure way to break clients.

Possible solutions:

1. Leave out osm_type completely to indicate a non-OSM source. This is already done with artificial postcodes, so clients must be able to handle that. We'd loose the parent information. osm.org uses it to go to the parent street when clicking on the result.
2. Add an additional source field. This could be generalized to any external data and combined with Different licence and copyright infomation for different data providers #1699.

Note that none of this will resolve that the source is shown on osm.org. Additional changes would be needed over there no matter what we do.

[mtmail]

@mtmail do you happen to have a reference to the discussion back then?

That might have been via email. It came up when https://github.com/osm-search/nominatim-ui was developed because while the old PHP HTML templates were able to infer a place came from TIGER data via internal variables the JSON/XML templates where missing the information. It remained an unsolved issue.

[mtmail]

Original test case no longer works because OSM mappers have added OSM house numbers around the location. New test case from another nominatim-docker discussion

1724 9th Avenue North, Bessemer, AL 35020, United States
https://nominatim.openstreetmap.org/ui/search.html?q=1724+9th+Avenue+North%2C+Bessemer%2C+AL+35020%2C+United+States