Marsman is a Dutch surname. It is either an occupational surname, with the meaning "peddler, hawker" (similar to the surname Kramer), or a toponymic surname, with more or less the meaning "marsh man".
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
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9ef81eb07789046389003b7f107aa7844529680c64929a4745c80f62d253664f. Chain 2 (Bitcoin): anchored in block 954580 (2026-06-20T17:48:00Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/b615e388-b48a-4c7a-8c16-2bdc1e6e21dc.json and https://artists.proofprofile.net/proofs/artist/b615e388-b48a-4c7a-8c16-2bdc1e6e21dc.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).