Talk:Key:subject:wikidata

Multiple values

I have a plaque mentioning two values: the brothers d:Q94626160 (Ferruccio Salvioni) and d:Q61481895 (Enrico Salvioni). For these cases, for maximum compatibility, I would propose to just use Multiple_values#Numbered_suffix_in_key so: subject:wikidata=* (maximum compatibility), plus subject:wikidata:1=*, subject:wikidata:2=* etc. --Valeriobozz (talk) 09:56, 6 December 2025 (UTC)

alt_subject:wikidata=* also may be used. Something B (talk) 13:52, 6 December 2025 (UTC)

This is a bad idea as other alt_*=*
There is 0 alt_subject=*
—— Kovposch (talk) 19:41, 6 December 2025 (UTC)

Why it is bad idea? alt_name=* works well… Something B (talk) 20:07, 6 December 2025 (UTC)

Why would you think this is maximum compatibility? What applications use numbered suffix? You should be aware there's the date suffix, meaning year-only is undefined between the two.
—— Kovposch (talk) 19:40, 6 December 2025 (UTC)

I just mean that we have some alternatives which are not sustainable, like introducing a semicolon/colon/pipe or whatever other separator to separate the two values in a single property. But having multiple values in a single property will break most (all?) current data consumers. Instead, with this proposal, we just introduce an additional attribute, so, at least 1 value is always read correctly, and the additional values are just potential "don't care" cases, but without breaking the first value. --Valeriobozz (talk) 20:48, 6 December 2025 (UTC)

I can see at least several dozen examples of Semicolon separated uses on subject:wikidata=* in the wild, so it seems it has already been introduced. Also, https://www.openstreetmap.org as well as https://overpass-turbo.eu correctly support them, so there is some data consumer support at least.

But it you're worried about data consumer support, I'd instead recommend creating (or using existing, of course) wikidata=* for the item itself, and then using multiple P180 "depicts" on that wikidata item to add multiple subjects depicted. As all OSM data consumers supporting wikidata that I've found so far just link to entry on https://wikidata.org, that would automatically give you widest possible support as well as allowing for better description of the item you're mapping. --mnalis (talk) 16:31, 7 December 2025 (UTC)

In theory, I agree with wikidata=* when possible; in practice, it is not feasible to create a Wikidata element for every single object like these - for scope issues and serious Wikidata scalability issues (https://phabricator.wikimedia.org/T335067) ... premising that the more we talk about this specific object... the more somebody may create a Wikidata item... lol. Anyway I note here that the kind user mnalis finalized this discussion by endorsing the subject:wikidata=* with the ";" separator. That sounds very good to me. Thanks again. I will add some notes in the wiki page (main namespace) to reflect this discussion. --Valeriobozz (talk) 16:06, 15 December 2025 (UTC)