After BRC-20 and ORC-20, What is BRC-21?

Following the explosive popularity of BRC-20, other asset standards built around the Bitcoin network have begun to emerge. On May 7, Alexei Zamyatin, founder of cross-chain interoperability project Interlay, proposed launching the BRC-21 standard to introduce fully decentralized cross-chain assets to the Bitcoin network and use them in the Lightning Network. Interlay Labs simultaneously released documentation for the BRC-21 token standard version 0.1.