Wikidata:Property proposal/front and backside

front- and backside

backside image

Originally proposed at Wikidata:Property proposal/Creative work

   Done: image of backside (P7417) (Talk and documentation)

Description	image of reverse side of a "2D"-object such as a photographic print, coin, etc.
Data type	Commons media file
Example 1	File:Culture, Medina at Fes Campaign - UNESCO - PHOTO0000002039 0001.tiff → File:Culture, Medina at Fes Campaign - UNESCO - PHOTO0000002039 0000.tiff
Example 2	File:View from Mount Holyoke, Northampton, Massachusetts, after a Thunderstorm—The Oxbow MET DP-12550-007.jpg → File:View from Mount Holyoke, Northampton, Massachusetts, after a Thunderstorm—The Oxbow MET DP-12550-002.jpg
Example 3	File:Giovanni di Paolo - Virgin and Child - WGA09479.jpg → File:Giovanni di paolo, madonna col bambino, 1445 ca. 02.JPG
Example 4	The Oxbow (Q3172259) → File:View from Mount Holyoke, Northampton, Massachusetts, after a Thunderstorm—The Oxbow MET DP-12550-002.jpg
Example 5	File:Huys Dever -Ego sum pastor bonus.jpg → File:Huys Dever -Dum medium silentium.jpg
See also	is recto of (P2681) (requires item, not available for images) has part(s) (P527) for artworks with an item and separate items for each side. Sample at Q27814872#P527 (with values Q20808326 and Q20808329). pendant of (P1639) for different objects

• We could use both proposed properties for Wikidata items about coins & emails, also. However, I oppose under the proposed name. Andy Mabbett (Pigsonthewing); Talk to Andy; Andy's edits 11:14, 13 September 2019 (UTC)

frontside image

Originally proposed at Wikidata:Property proposal/Creative work

   Done: image of frontside (P7418) (Talk and documentation)

Description	image of obverse of a "2D"-object such as a photographic print, coin, etc.
Data type	Commons media file
Example 1	File:Culture, Medina at Fes Campaign - UNESCO - PHOTO0000002039 0000.tiff → File:Culture, Medina at Fes Campaign - UNESCO - PHOTO0000002039 0001.tiff
Example 2	File:Giovanni di paolo, madonna col bambino, 1445 ca. 02.JPG → File:Giovanni di Paolo - Virgin and Child - WGA09479.jpg
Example 3	File:Huys Dever -Dum medium silentium.jpg → File:Huys Dever -Ego sum pastor bonus.jpg
See also	is verso of (P2682) (requires item, not available for images)

• 
  from c:Category:Media files produced by UNESCO: 2019-09
• 
  backside, from c:Category:Media files produced by UNESCO: 2019-09 (reverse)
• 
  The Oxbow (Q3172259)
• 
  backside
• 
  Virgin and Child (Q67471525)
• 
  backside
• 
  front
• 
  back

Motivation

c:Category:Media files produced by UNESCO: 2019-09 looks like it could use this. Please add more samples. (Add your motivation for this property here.) --- Jura 10:44, 13 September 2019 (UTC)

Discussion

•  Support if created they should have inverse constraint (Q21510855) for property constraint (P2302), one each other. Christian Ferrer (talk) 11:02, 13 September 2019 (UTC)
  • I think I can strike my support as is recto of (P2681) and is verso of (P2682) already exist, (and already with the useful property constraint mentioned above.) Christian Ferrer (talk) 05:55, 14 September 2019 (UTC)
    • Oups I did not see that the data type is different, I  Support (still with the useful property constraint mentioned above) Christian Ferrer (talk) 09:32, 14 September 2019 (UTC)
  • They should not; consider their use for coins. Andy Mabbett (Pigsonthewing); Talk to Andy; Andy's edits 11:15, 13 September 2019 (UTC)
    • ? this property is for front and backside of the same specific object, coins or not. For another use then that should be another property. Christian Ferrer (talk) 09:32, 14 September 2019 (UTC)
•  Oppose The proposed relation is between two digital representations of a single object; I think this is the wrong way to model it. The subject of such a relation should be the object itself (i.e. an item representing the object), not its digital representation. And I think we already have a property that handles this: digital representation of (P6243) - just attach a qualifier to indicate which side of the object is being represented by the file. ArthurPSmith (talk) 16:40, 13 September 2019 (UTC)
•  Oppose Agree with ArthurPSmith - two images with a qualifier seems the best way to handle this relationship. See eg Standard of the Flagellation (Q3973083) or Three Standing Figures (recto); Seated Woman and a Male Hermit in Half-length (verso) (Q29384920), which use recto (Q9305022) & verso (Q9368452), or United States one-dollar bill (Q1058210) & 1804 silver dollar (Q4553821) which use obverse (Q257418) and reverse (Q1542661) (there being different conventions for art + money). The same sets of qualifiers are also used for transcriptions (Phaistos disc (Q465338)), depicts (denarius of L. Censorinus (Q5256588)) etc, so this is a fairly consistent system. Andrew Gray (talk) 18:56, 13 September 2019 (UTC)
  • @Andrew Gray: I understand that it may be theoretially appealing, but I don't think it's a good idea to make separate items for Commons files happen to based on a scan of a printed photograph. --- Jura 19:01, 13 September 2019 (UTC)
  • As for paintings with two sides, I don't think the samples given above are ones to follow. Three angels (Q27814872) given by Jane023 at c:Commons_talk:Structured_data#Obverse_and_reverse_images seems superior, especially as it includes Q27814872#P527 with items for each site: it's important to be able to reference, study and describe each painting separately. Something that isn't needed for File:Culture, Medina at Fes Campaign - UNESCO - PHOTO0000002039 0000.tiff --- Jura 19:27, 13 September 2019 (UTC)
    • @Jura1: Good catch - I think I had assumed this would be used for existing items describing the works, rather than new items for each image file (which, as you say, is not desirable on Wikidata). Presumably the property as described would be useful for structured data on Commons but not intended to be used on Wikidata items? That seems more reasonable.
    • (For paintings with two sides where both are significant works in their own right, agree two items makes sense.) Andrew Gray (talk) 19:37, 13 September 2019 (UTC)
      • @Andrew Gray: is there some aspect of your oppose we haven't addressed yet. I'd try to include it. --- Jura 08:57, 20 September 2019 (UTC)
        • @Jura1: If it's clear this is for linking media files together rather than for use on normal items, I'm fine to  Support the proposal with those limits. It certainly sounds useful. I agree with Arthur that it might be simplest to just have one property - "image showing other side". Andrew Gray (talk) 10:25, 22 September 2019 (UTC)
      • The first one might also have a use for cases like the oxbow sample above (fixed the filename just now, see comment below). --- Jura 17:09, 23 September 2019 (UTC)
•  Support Jane023 (talk) 19:51, 13 September 2019 (UTC)
•  Comment. Just for your information. When it comes to opposite sides of an object, is recto of (P2681) and is verso of (P2682) do exist, as P1432 (P1432) also does. Thierry Caro (talk) 02:31, 14 September 2019 (UTC)
  • @Thierry Caro, Christian Ferrer: datatype is different. --- Jura 09:22, 14 September 2019 (UTC)
  • @Thierry Caro: do you think there something else that needs adding? --- Jura 08:56, 20 September 2019 (UTC)
•  Comment Ok, if this is intended ONLY to apply to commons files which have no associated item, they why is more than one property needed? Something like "image of opposite side" would cover both cases just fine. ArthurPSmith (talk) 14:02, 16 September 2019 (UTC)

 Question Will the inverse constraint work with itself? I guess yes... Christian Ferrer (talk) 17:41, 16 September 2019 (UTC)

It would be a symmetric constraint (Q21510862) in that case. ArthurPSmith (talk) 19:51, 16 September 2019 (UTC)

It's hard to say what would be easier to use. I added a few samples for paintings that aren't directly linked.--- Jura 22:49, 19 September 2019 (UTC)

• @Jane023: maybe The Oxbow (Q3172259) could use the first property to link to File:View from Mount Holyoke, Northampton, Massachusetts, after a Thunderstorm—The Oxbow MET DP-12550-002.jpg. --- Jura 22:49, 19 September 2019 (UTC)
  • Yes that would work. Actually you might get more votes by suggesting both properties for a WGA painting currently lacking an item. So the main point of this proposal is that my original comment in the Commons discussion doesn't work. There I said that you need a Commons-based placeholder for the "thing itself" which normally lives on Wikidata for notable paintings. As far as the recto/verso thing goes, your proposal applies beter to e.g. this: File:Huys Dever -Ego sum pastor bonus.jpg as well. Jane023 (talk) 07:25, 20 September 2019 (UTC)
    • @Jane023: At this stage, I mainly try to integrate and improve the proposal based on constructive input received (or formulate an entirely different one). I think it's important to delimit the proposal to properties used for two-sided artworks (done above now). Also to use for actual backsides of paintings hadn't occurred to me, but somehow it does seem missing. I think some art historians like to see them even if images aren't necessarily easily available (added the sample above now). File:Giovanni di Paolo - Virgin and Child - WGA09479.jpg mentioned above didn't actually have an item prior to this proposal. --- Jura 08:56, 20 September 2019 (UTC)