N/A (or sometimes n/a or N.A.) is a common abbreviation in tables and lists for the phrases not applicable,Barbara H. Foley, English In Action (2003), p. 192.Alan C. Kay, J., Metzler Contracting Co. L
1. Compute SHA-256 of OTSCanonicalRecord value → must equal OTSHash 2. Open OTSProofURL → extract Bitcoin block number → must equal OTSBitcoinBlock 3. GET OTSBitcoinBlockVerifyURL → returns the Bitcoin block hash at height OTSBitcoinBlock; GET https://blockstream.info/api/block/{that hash} → its timestamp must match OTSTimestamp 4. Read CopyrightID inside OTSCanonicalRecord → must equal the CopyrightID above 5. GET OTSVerificationAPI → pre-computed 6-check result from server 6. If all match: this entity was registered on CopyrightChains at OTSTimestamp, independently verifiable on Bitcoin Note: an OTS proof may carry multiple Bitcoin attestations; OTSBitcoinBlock is the earliest confirmed one — a later attestation inside the proof corroborates it and is not a mismatch
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1ad189ddd1f3d35a054e7e0ef651d7c1478ab895a3d8a3e2cee0a2a3b34c4dd1. Chain 2 (Bitcoin): anchored in block 954667 (2026-06-21T07:29:20Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/b7b211e7-0e23-4b6f-89af-c99e9f06e657.json and https://artists.proofprofile.net/proofs/artist/b7b211e7-0e23-4b6f-89af-c99e9f06e657.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).