>"The IDF designed the DOI system to provide a form of persistent identification, in which each DOI name permanently and unambiguously identifies the object to

>"The IDF designed the DOI system to provide a form of persistent identification, in which each DOI name permanently and unambiguously identifies the object to which it is associated..." Related: https://en.wikipedia.org/wiki/ISBN https://en.wikipedia.org/wiki/ISBN https://en.wikipedia.org/wiki/Publisher_Item_Identifier https://en.wikipedia.org/wiki/Publisher_Item_Identifier https://en.wikipedia.org/wiki/Library_of_Congress_Control_Number https://en.wikipedia.org/wiki/Library_of_Congress_Control_Nu... https://en.wikipedia.org/wiki/Amazon_Standard_Identification_Number https://en.wikipedia.org/wiki/Amazon_Standard_Identification... https://en.wikipedia.org/wiki/Accession_number_(cultural_property) https://en.wikipedia.org/wiki/Accession_number_(cultural_pro... PDS: I wonder how many other systems there are, national and international, for uniquely identifying content? There are probably quite a whole lot of these -- everything from UUID's to file hashes, to numbering systems created by professional organizations, like the IEEE, IETF RFC Numbers, etc. etc. I think it would be an interesting project to research all of those -- both national and international, current and historical -- and create a canonical list of all of them...