Neo has finalized its NFT royalty standard, assigned as NEP-24. The standard describes an extension to NEP-11 NFT smart contracts that will allow them to disclose royalties to be honored on re-sales of the asset.

The standard describes the implementation of a new method, royaltyInfo, which NFT contracts can add and use to specify single or multiple royalty recipients. Royalty amounts are specified on a per-recipient basis, and can be calculated dynamically by a marketplace depending on the sale price.

This mechanism ensures that different NFT marketplaces can agree on the correct figures to pay out. In addition, supporting the standard requires marketplaces to emit a new event, RoyaltiesTransferred, once for each payout recipient.

Two implementation examples have been provided as part of the standard. The first is taken from a Python NFT template by GhostMarket, an early adopter of the standard, and the second was added as a new C# NFT contract example in the neo-devpack-dotnet.

Developers can read more about the standard and how to integrate it with their own projects at the link below:
https://github.com/neo-project/proposals/blob/master/nep-24.mediawiki