I happened to pass by this previously if it is helpful...
From
https://blockgeeks.com/guides/fungible-vs-non-fungible-tokens-what-is-the-difference/.
several projects have started issuing NFT tokens. One of those happens to be RSK.
What is RSK?
Rootstock (RSK
https://www.rsk.co/) is a smart contract platform that is connected to the Bitcoin blockchain through sidechain technology. Rootstock was born to be compatible with Ethereum’s applications (the web3/EVM/Solidity model) . The idea behind the creation of RSK was to give the Bitcoin blockchain smart contract functionalities. At its very core, Rootstock is a combination of:
A Turing-complete resource-accounted deterministic virtual machine (for smart contracts) compatible with Ethereum’s EVM.
A two-way pegged Bitcoin sidechain (for BTC denominated trade) based on a strong federation.
A SHA256D merge-mining consensus protocol (for consensus security relying on Bitcoin’s miners) with 30-seconds block interval. (for fast payments).
RSK: NFT Use Cases
Its partnership with Watafan can perfectly describe RSK’s advances in the field of non-fungible tokens.
Watafan will allow celebrities to create their own digital trading cards, aka watacards.
Celebrities can give away the watacards to their fans as a gift or autograph.
They can use their personal wallet to sign these cards cryptographically.
Smart contracts protect the intellectual property of the idols.
Every time fans trade watacards in the secondary market among each other. The concerned celebrity will receive a chunk of the shares.
Watafan aims to propel the digital property to the next level by leveraging smart contracts. Watafan idols can secure their copyright and digital identity with RSK smart contracts.
Long-term, watacards will cement themselves as a new kind of asset that can help preserve the intellectual copyrights of artists, athletes, musicians, actors, and others.
How to build an RSK NFT?
Here´s a good resource to get started coding your non-fungible token and a video with step-by-step instructions to create your own collectable token on RSK´s network.