Hi, I started a discussion on the materials project to find out the best way to list material standards. It is a long topic so that the discussion is on the project page : https://www.wikidata.org/wiki/Wikidata_talk:WikiProject_Materials/Properties It would be nice to have some advice from experimented Wikidata users. ;-) Regards -- Thibaut DEVERAUX +33 (0)6 75 51 20 80