Story here. Excerpt:
"Del Pesco then reconnected with an old friend, Lauren van Haaften-Schick, a curator and writer who was researching this very topic for her PhD dissertation at Cornell University. Along with the art lawyer Laurence Eisenstein, she helped draft a document that designates that 15% of resale profits go to a charitable organisation of the artist’s choice. The agreement is available online at artistcontract.org, and will soon be promoted by Kadist Art Foundation."
I participated in a really interesting roundtable with van Haaften-Schick on the subject of resale royalties a couple summers ago. Link here.