Optional
initialThe initial DID Document for an externally created did:btc1, if not fetched from IPFS or another CAS.
Optional
signalsA map from Bitcoin transaction IDs to the sidecar info about that signal. Each signal might provide a single DID Update Payload, or (for aggregator beacons) a bundle or proofs.
A container for out-of-band data the resolver may need. This includes the initial DID document if it isn't stored in IPFS, plus references for each on-chain Beacon signal.
DID BTC1 4.2.1.2.1 Sidecar Initial Document Validation, 4.2.2 Resolve Target Document, 4.2.2.2 Traverse Blockchain History, 4.2.2.3 Find Next Signals.