International Standard Name Identifier is new metadata to resolve name ambiguity for contributors to creative works. This number can define a person, like a writer, artist, performer, producer, etc., or it can define an organization, like publishers, studios, aggregators, etc..
The newest metadata standard for music is here apparently and it is RIN-M. Soundways has a free plugin that gets saved in your DAW when you are creating the tracks and you can add everyone's information and send it along. It is a cool idea on solving the issue with how recording credits are stored and transferred. You can download the plugin here.