According to BitMEX Research, Rare Pepe assets on Bitcoin use the OP_RETURN field to record a URL to the image rather than embedding the image itself, meaning only the reference is on-chain while the media is off-chain (source: BitMEX Research on X, Sep 21, 2025). BitMEX Research cited transaction 0c6e1608c64ab0bad80d3435449ef347c3b6d4048869ee51f2c647c50d0d2337 on mempool.space as an example of OP_RETURN-based metadata used in Rare Pepe trading (source: BitMEX Research on X, Sep 21, 2025; source: mempool.space transaction page). For traders in BTC NFT markets, this indicates due diligence should focus on verifying the on-chain OP_RETURN URL and related issuer data rather than expecting image payloads to be stored on-chain (source: BitMEX Research on X, Sep 21, 2025).