Fairly rare occurrence, but I came across it today while using SC.

There was a road tagged with name and name:etymology:wikidata
A road adjoining this did not have a name (but should have had the same name).

When I went to answer the "What is the name of this street" quest it looked something like this (with en and etymology:wikidata filled in appropriately)

This looks quite confusing as the wikidata value is something like Q123456 (so looks nothing like a name).

I left it as default to see what would happen and when I got back I checked and saw that this had added name, name:en (same as name) and name:etymology:wikidata.

I think the quest should probably add etymology if the road name is identical, but perhaps without showing it to the user.
It should not add name:en (or whichever language code) if there's only one actual name (such as this case).

A look through the first few pages on taginfo when searching for name: shows up some things that should be checked for and treated differently:
name:etymology:wikidata (153700 uses)
name:etymology:wikipedia (27300 uses)
name:etymology (11,800 uses)
name:source (9800 uses) (likely a synonym for source:name, and would probably be better as that for reasons like this)
name:wikipedia (3800 uses)
name:adjective (3060 uses)
name:pronunciation (2850 uses)
name:etymology:description (2720 uses)