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 0x02cde16f617938159b6dc88a49c18e9c686d639f2c11ea405f7a50d2909c7bd7. Chain 2 (Bitcoin): anchored in block 953407 (2026-06-12T19:24:56Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/ab03133e-b3d6-4375-8f13-573d430af9e6.json and https://artists.proofprofile.net/proofs/artist/ab03133e-b3d6-4375-8f13-573d430af9e6.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
1. Confirm isrcCode identifies the recording in the pre-2022 source corpus and cc-db-prod record 2. GET OTSVerificationAPI → server-side canonical-record, hash, and attestation checks must pass 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. Confirm CopyrightID is the CopyrightChains transaction hash 5. If all match: the cc-db-prod record is independently anchored on Bitcoin at OTSTimestamp 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 0x36f144b2767e9e2e26ef31f77951f62c2a09206fba8f7d38af86b2f57cf05b8b. Chain 2 (Bitcoin): anchored in block 958975 (2026-07-21T08:42:17Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/QZNWT2137677.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x37a7aa4b3f414eb907e1f4dab4fb4b24d209e01fbe018ea43cfc2a44cd0f69d5. Chain 2 (Bitcoin): anchored in block 958631 (2026-07-19T00:50:09Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/QZTAS2105775.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x064b35dddc943f386c47152d4c74dca502eddce3c40326f140593c6d314b11bc. Chain 2 (Bitcoin): anchored in block 958722 (2026-07-19T11:03:50Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/QZDA72203996.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xacc4c9db1374d88ddcdbc89b355cb302a2f81b47e8edca67b694ebbaa6376079. Chain 2 (Bitcoin): anchored in block 958965 (2026-07-21T04:29:05Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/QZES92239190.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7900661717d5a2c5ca824c1d4f8b6749604bb7373545be80c7437c60c25358ee. Chain 2 (Bitcoin): anchored in block 958796 (2026-07-20T02:15:51Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/QZK6K2304063.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x656a8c82b9541746f1504fcfca104290699f5c7877382b13d470f6e832f73d6c. Chain 2 (Bitcoin): anchored in block 958529 (2026-07-18T09:21:41Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/QZMER2333055.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4093c6c5424bcb86ec6dc7543f846946761758bd62e2f29b982c48fba3b2ea6d. Chain 2 (Bitcoin): anchored in block 956420 (2026-07-03T00:42:11Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/QZNWU2343422.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf40aad433993bf58fb63675ac980a859a1a18ca669142aade7f4800757a26792. Chain 2 (Bitcoin): anchored in block 956634 (2026-07-04T10:04:33Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/QZFZ32403096.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd4d2f8da7af1c96103c07388ce306a2f408cc9ba878bc988f5d3958db0dae598. Chain 2 (Bitcoin): anchored in block 958885 (2026-07-20T15:59:57Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/QZES72430883.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x74c04826672a63c4eaf691f089a0fa4005c5738ec80b69e038795a43d10f0c10. Chain 2 (Bitcoin): anchored in block 956725 (2026-07-05T01:12:41Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/QZHN72460013.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc5bc1e15c8878211bc9dfb5e88f95cbe3f9001671438f1f8028cc13c0628c6f7. Chain 2 (Bitcoin): anchored in block 959001 (2026-07-21T11:41:42Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/QZHN72462178.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x12fd6df277f4880f3a9ecd7d6bb521c76296f7bed4ec785c973e67c5aa8b8fdd. Chain 2 (Bitcoin): anchored in block 958607 (2026-07-18T21:01:11Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/TCAIH2408274.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7ebab16b5d14a8c917676915ff62e5264d57c56e29f12966ae0724b01c678382. Chain 2 (Bitcoin): anchored in block 956634 (2026-07-04T10:04:33Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/TCAII2408309.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x358ab787ca9968e7fc24236c7a32ba37971476d63fa14c0e9fe6be1a61390f35. Chain 2 (Bitcoin): anchored in block 958955 (2026-07-21T03:03:40Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/TCAIH2408443.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe27d09dee5cb98b9e46e399a50f07142a265e2ae50e22a1dfb313055d0d11d5e. Chain 2 (Bitcoin): anchored in block 958510 (2026-07-18T06:38:22Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/TCAIH2408487.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7e7e9e714c54aaf39aa99768a17cbaa30cf180685814701222291abd290f492a. Chain 2 (Bitcoin): anchored in block 958461 (2026-07-17T23:18:11Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/QZZ7L2448594.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x914121a61df0fe9715b39fd3db9ea8c8569aa0b0885f855acf246411e108e152. Chain 2 (Bitcoin): anchored in block 958166 (2026-07-15T18:31:07Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/QT3EZ2460346.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x88d5f1114e3176d102b4b447aa4118866dd8420cf88cd6dc0643689f4af5788c. Chain 2 (Bitcoin): anchored in block 959094 (2026-07-22T03:33:16Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/QT3EZ2460352.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x722d35748a4c9f54887cccefe17c6c9886837c6e0f213769fecdcfe2f5b298fa. Chain 2 (Bitcoin): anchored in block 958830 (2026-07-20T05:30:12Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/QT3EZ2460353.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x79017ef41097c73f427008711c319d1b0d4e6688458d0934870783963e711231. Chain 2 (Bitcoin): anchored in block 958796 (2026-07-20T03:00:49Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/QT3EZ2460354.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x88d5f1114e3176d102b4b447aa4118866dd8420cf88cd6dc0643689f4af5788c. Chain 2 (Bitcoin): anchored in block 958224 (2026-07-16T02:28:43Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/QT3EZ2460352.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x722d35748a4c9f54887cccefe17c6c9886837c6e0f213769fecdcfe2f5b298fa. Chain 2 (Bitcoin): anchored in block 958216 (2026-07-16T00:00:34Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/QT3EZ2460353.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x79017ef41097c73f427008711c319d1b0d4e6688458d0934870783963e711231. Chain 2 (Bitcoin): anchored in block 958111 (2026-07-15T06:58:20Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/QT3EZ2460354.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x552cd43fef0b1f5b505176fca53fb12b4cfc9e906e3f7ffc95ffb6e7bcc0cef1. Chain 2 (Bitcoin): anchored in block 956375 (2026-07-02T16:51:38Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/QZES82567658.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x831ae3baa5384979024d523176c1c5da03796cddf0162c7e20497ad9d5867057. Chain 2 (Bitcoin): anchored in block 956375 (2026-07-02T16:51:38Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/QZES82567660.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3858a58cea0fd44259f01fee880c079f20adcb82a733dc3aacd5b2fe1b282770. Chain 2 (Bitcoin): anchored in block 958286 (2026-07-16T12:43:37Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/QZES82567661.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xba630664bcd57c8102d6e4fe4e83e43841f88abd29ad66aac045069703746963. Chain 2 (Bitcoin): anchored in block 958276 (2026-07-16T12:48:42Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/QZES82567662.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x77de1c24d4559b3fc62fa9667f1771227f32c6ae881877123c7dc309ffe74a66. Chain 2 (Bitcoin): anchored in block 957785 (2026-07-13T01:55:31Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/CH7812539012.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd5de18ff28622409ab37f6d6a6fe084504aa0a85866f747389d7e7f0727fcc19. Chain 2 (Bitcoin): anchored in block 957775 (2026-07-13T00:04:23Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/QZQAY2529697.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb86ee5cd8674cc732fe6b85cff853741133cf4bb93c2bd8ff35d3218244b0e24. Chain 2 (Bitcoin): anchored in block 957785 (2026-07-13T01:55:31Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/QZQAY2594869.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9e45fa13de9eb92dbfb9f178d8915f0a9a5eae28b2e1e2c451461bab34cc3640. Chain 2 (Bitcoin): anchored in block 958335 (2026-07-17T00:58:35Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/QZTLA2598584.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x56c8b6b6988f41e950f7bf3aca3c332647879a7eece815ca49e9e8d51dd47748. Chain 2 (Bitcoin): anchored in block 956474 (2026-07-03T08:56:35Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/QZSYP2555572.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x94db403b72a785a8e9d81b513296fd3f7cce38254eb538e93ff1356060642767. Chain 2 (Bitcoin): anchored in block 956634 (2026-07-04T10:04:33Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/QZSYP2568847.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4e1ed6e0f1087facd6adf28e812d3c2a8b3c6dbb09eb02c992f10a8105d03237. Chain 2 (Bitcoin): anchored in block 958444 (2026-07-17T19:12:23Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/QZQAY2535198.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x709aaee1df2f0d0034e802f6d393fd2ad78ec8ece4bf1c28fc80202103fd7e8d. Chain 2 (Bitcoin): anchored in block 956634 (2026-07-04T10:04:33Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/QZQAY2521873.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2627d222a1cdd63d65f33d6a2245b04d564a5eb78c5d7c35ed5464691c324a94. Chain 2 (Bitcoin): anchored in block 956725 (2026-07-05T01:12:41Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/QZQAY2519265.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7b0c41f28c6def20ca0510d0783d53c2ab5073eca1eb0a872139adf036302ad8. Chain 2 (Bitcoin): anchored in block 956772 (2026-07-05T10:01:46Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/QZQAY2573487.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xde3c0d8af010915fe1a1b9b7f439fd804ea5847b7536df855f8479ed8488b85e. Chain 2 (Bitcoin): anchored in block 956772 (2026-07-05T10:01:46Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/QZQAY2544082.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x97444a6e65bb205d9dffe36b8746507b01ed88f85e7354e9b11187f43bddd3d4. Chain 2 (Bitcoin): anchored in block 956725 (2026-07-05T01:12:41Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/QZS7J2577535.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x55c3193cf2e67885b4637ae9567309c14242b005afac644acdf83186d966d3cf. Chain 2 (Bitcoin): anchored in block 956304 (2026-07-02T03:55:08Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/CA5KR2358299.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc2c8ea9185f77195bf564755afafc8903b8494a301bdf64200fa28f02a6992cd. Chain 2 (Bitcoin): anchored in block 953520 (2026-06-13T13:32:09Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/CA5KR2358304.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3a2b0c802ce9af61f31ccb17a546389e128a1e36fa0b9fdbf1a99f5d98133d32. Chain 2 (Bitcoin): anchored in block 956304 (2026-07-02T03:55:08Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/CA5KR2358305.