Namespace They claim to have developed it across multiple Blockchains. But not on top of Bitcoin. A few proposals are also being listed here. https://github.com/ordinals/ord/issues/1838 For the hackernoon + namespaces you can read this. https://hackernoon.com/namespacegg-a-solution-to-the-centralized-identity-crisis

These are a few of the identities I could find that are en route to making it possible. Hopefully earlier than anticipated