from github :

NIP-94

File Metadata

draft optional author:frbitten author:kieran author:lovvtide author:fiatjaf

The purpose of this NIP is to allow an organization and classification of shared files. So that relays can filter and organize in any way that is of interest. With that, multiple types of filesharing clients can be created. NIP-94 support is not expected to be implemented by "social" clients that deal with kind:1 notes or by longform clients that deal with kind:30023 articles.