This strives to be an easier implementation of https://spec.scuttlebutt.nz/feed/datamodel.html feeds.
Apart from making it easier to implement this (since the v8 specific JSON quirks go away), the most important improvement over the legacy format is off-chain content. This means only the hash of the content is signed and is committed on the chain.
Replication will stay very similar as well, by grouping metadata and content into the transfer structure, omitting the content if it was delete by the remote.
It will also use the same cryptographic primitives ed25519 and sha256.
See draft-ssb-core-gabbygrove/00/ at the https://github.com/ssbc/ssb-spec-drafts repository for a (hopefully) complete specification.
MIT