Also … when artists post their cool creations (see bellow) to social media… I wonder if such a NIP could be used to help them verify original ownership? (Maybe a stretch, but just an example of the many ways that verification of external web properties could be valuable on nostr)

mostr:note1lqcy0gcqdxhzrcgnwtatm3pkahv2465lhr62kewwqyhh3lvyvxjs3474y9 

 Sure, if you go here and look at the raw event data (in the three-point menu) then you can see what can be included in the object hash.

https://nostrudel.ninja/#/n/note1lqcy0gcqdxhzrcgnwtatm3pkahv2465lhr62kewwqyhh3lvyvxjs3474y9