{ "vercy": "1.0-draft", "publication": { "status": "research-draft", "adjudicationStatus": "unreviewed", "publishableCanonical": false, "generatedAt": "2026-10-22T11:44:46Z", "providers": [ "Claude" ], "breadth": "researched by Claude against the sources listed below", "pass": 2, "wave": 5, "engine": "claude", "gate": { "passed": true, "version": "1.0", "at": "2026-10-22T12:05:11+00:00", "evidence": [ "completeness 1.00", "sense: Wikidata description", "7 live sources", "review by codex: pass" ] } }, "metaModel": { "id": "THING-Q34467", "registryId": "vr.tr.compact-disc", "name": "compact disc", "version": "0.2.0-wave.5", "entryKind": "thing", "family": "Thing Registry", "domain": [ "PHY.OBJ" ], "status": "research-draft" }, "canonicalUrl": "https://ver.cy/models/thing/q34467/", "model": { "registry_id": "vr.tr.compact-disc", "name": "compact disc", "purpose": "Let an agent explain the compact disc format, its variants, specifications and preservation, from standards and archival sources.", "definition": "A digital optical disc data storage format developed by Philips and Sony and released in 1982, typically 120 mm in diameter, read by a 780 nm laser; first used for digital audio (CD-DA, Red Book, 44.1 kHz 16-bit stereo, up to about 74-80 minutes) and later for data (CD-ROM), recordable (CD-R) and rewritable (CD-RW) media.", "what_it_is_for": "Storing and distributing digital audio and data.", "affordances": [ "explain formats and specifications", "explain capacity and audio parameters", "explain care and preservation", "explain identifiers such as ISRC on CDs" ], "distinguishing_features": [ "Audio CD is specified in the Red Book (IEC 60908); CD-ROM in the Yellow Book (ISO/IEC 10149); data uses EFM coding and CIRC error correction.", "Pressed discs have moulded pits; CD-R uses a dye layer and CD-RW a phase-change layer.", "Typical capacity about 650-700 MB of data or 74-80 minutes of audio." ], "appearance": "A thin, shiny polycarbonate disc 120 mm across with a central hole, iridescent on the data side.", "visual_identification": [ "Iridescent 12 cm disc with the Compact Disc logo" ], "physical_properties": [ { "quantity": "diameter", "typical_range": "120", "unit": "mm", "note": "80 mm mini CD also exists" }, { "quantity": "thickness and centre hole", "typical_range": "1.2 mm thick, 15 mm hole", "unit": "", "note": "nominal" }, { "quantity": "audio format", "typical_range": "44.1 kHz, 16-bit, 2 channels", "unit": "", "note": "Red Book" } ], "families_and_kinds": [ "CD-DA (audio)", "CD-ROM", "CD-R", "CD-RW", "Mini CD", "Video CD", "Enhanced CD" ], "related_models": [ { "relation": "is a kind of", "target": "optical disc", "why": "storage medium" }, { "relation": "is succeeded by", "target": "DVD", "why": "format" }, { "relation": "is related to", "target": "Super Audio CD", "why": "distinct format; hybrids carry a CD layer" }, { "relation": "uses", "target": "laser", "why": "reading technology" } ], "identifiers": [ { "scheme": "ISRC", "value_or_pattern": "12 characters", "note": "tracks" }, { "scheme": "UPC/EAN", "value_or_pattern": "12 or 13 digits", "note": "releases" }, { "scheme": "IFPI SID code", "value_or_pattern": "on the disc", "note": "manufacturing plant" } ], "standards_and_regulation": [ "IEC 60908 (Red Book, CD-DA)", "ISO/IEC 10149 (Yellow Book, CD-ROM)", "ISO 9660 file system", "ISO 18927:2013 recordable-CD life expectancy (withdrawn)" ], "failure_modes_and_hazards": [ "Disc rot and dye degradation", "Scratches causing read errors" ], "agent_conduct": { "may": [ "explain formats and preservation" ], "must_not": [ "help circumvent copy protection unlawfully" ], "requires_human": [] }, "ethics": { "considerations": [ "copyright", "digital preservation" ], "affected_parties": [ "artists", "archives" ] }, "owners": { "steward": "nobody; a format; the specifications are licensed and standardised", "master_systems": [] }, "facets_not_applicable": {}, "in_scope": [], "out_of_scope": [], "characteristics": [] }, "sources": [ { "id": "SRC-001", "title": "Q34467", "publisher": "Wikidata", "url": "https://www.wikidata.org/wiki/Q34467", "what_it_supports": "identity of the registry item, labels and sitelinks", "url_status": "live" }, { "id": "SRC-002", "title": "Compact disc", "publisher": "Wikipedia", "url": "https://en.wikipedia.org/wiki/Compact_disc", "what_it_supports": "general description of the subject", "url_status": "live" }, { "id": "SRC-003", "title": "IEC 60908:1999 - Audio recording - Compact disc digital audio system", "publisher": "International Electrotechnical Commission", "url": "https://webstore.iec.ch/en/publication/3885", "what_it_supports": "Audio-CD standard scope and issuing body.", "url_status": "live" }, { "id": "SRC-004", "title": "ECMA-130: Data interchange on read-only 120 mm optical data disks", "publisher": "Ecma International", "url": "https://ecma-international.org/publications-and-standards/standards/ecma-130/", "what_it_supports": "CD-ROM dimensions, optical reading, channel coding, error correction and ISO/IEC 10149 correspondence.", "url_status": "live" }, { "id": "SRC-005", "title": "ISO 18927:2013", "publisher": "International Organization for Standardization", "url": "https://www.iso.org/standard/62635.html", "what_it_supports": "Withdrawn status and temperature/humidity life-expectancy test scope.", "url_status": "blocked" }, { "id": "SRC-006", "title": "Care and Handling of CDs and DVDs: A Guide for Librarians and Archivists", "publisher": "National Institute of Standards and Technology", "url": "https://nvlpubs.nist.gov/nistpubs/legacy/sp/NISTspecialpublication500-252.pdf", "what_it_supports": "Disc construction, dimensions, dye and phase-change media, degradation and preservation.", "url_status": "live" }, { "id": "SRC-007", "title": "New Sound Recording Formats - Library of Congress Practice", "publisher": "Library of Congress", "url": "https://www.loc.gov/catdir/cpso/soundrec.pdf", "what_it_supports": "SACD as a distinct format and the existence of hybrid and non-hybrid SACDs.", "url_status": "live" }, { "id": "SRC-008", "title": "International Standard Recording Code", "publisher": "IFPI, International ISRC Registration Authority", "url": "https://isrc.ifpi.org/", "what_it_supports": "ISRC has 12 alphanumeric characters and identifies recordings rather than physical discs or releases.", "url_status": "live" } ], "structure": { "bundles": [ { "id": "disc", "name": "Disc", "description": "Which disc.", "rationale": "Format first.", "layers": [ { "id": "format", "name": "Format", "description": "Type.", "findings": [ { "id": "format", "name": "Format", "description": "Physical medium (pressed, CD-R, CD-RW) and logical format (audio or data), recorded separately.", "questions": [ { "text": "CD-DA, CD-ROM, CD-R or CD-RW?", "kind": "boundary" }, { "text": "Per which specification?", "kind": "provenance" } ] } ] }, { "id": "release", "name": "Release", "description": "Item.", "findings": [ { "id": "release", "name": "Release", "description": "Identifier.", "questions": [ { "text": "Which release?", "kind": "provenance" }, { "text": "Which UPC or catalogue number?", "kind": "provenance" } ] } ] } ] }, { "id": "specification", "name": "Specification", "description": "Technical data.", "rationale": "Standards define it.", "layers": [ { "id": "physical", "name": "Physical", "description": "Dimensions.", "findings": [ { "id": "physical", "name": "Physical", "description": "Values.", "questions": [ { "text": "What diameter and thickness?", "kind": "measurement" }, { "text": "Per which standard?", "kind": "provenance" } ] } ] }, { "id": "data", "name": "Data", "description": "Capacity.", "findings": [ { "id": "capacity", "name": "Capacity", "description": "Value.", "questions": [ { "text": "What capacity or duration?", "kind": "measurement" }, { "text": "Per which format?", "kind": "provenance" } ] } ] } ] }, { "id": "content", "name": "Content", "description": "Tracks.", "rationale": "Tracks have identifiers.", "layers": [ { "id": "tracks", "name": "Tracks", "description": "List.", "findings": [ { "id": "track", "name": "Track", "description": "Title and ISRC.", "questions": [ { "text": "Which tracks?", "kind": "provenance" }, { "text": "Which ISRCs?", "kind": "provenance" } ] } ] }, { "id": "rights", "name": "Rights", "description": "Copyright.", "findings": [ { "id": "rights", "name": "Rights", "description": "Holder.", "questions": [ { "text": "Who holds the rights?", "kind": "provenance" }, { "text": "Per which credit?", "kind": "provenance" } ] } ] } ] }, { "id": "preservation", "name": "Preservation", "description": "Care.", "rationale": "Discs degrade.", "layers": [ { "id": "condition", "name": "Condition", "description": "State.", "findings": [ { "id": "condition", "name": "Condition", "description": "Assessment.", "questions": [ { "text": "What is the disc condition?", "kind": "provenance" }, { "text": "Measured by error rate?", "kind": "measurement" } ] } ] }, { "id": "storage", "name": "Storage", "description": "Conditions.", "findings": [ { "id": "storage", "name": "Storage", "description": "Recommendation.", "questions": [ { "text": "How should it be stored?", "kind": "provenance" }, { "text": "Per which archival guidance?", "kind": "provenance" } ] } ] } ] } ] }, "openQuestions": [ "The registry merges multi-disc packages and other formats; they need review." ], "statistics": { "bundles": 4, "layers": 8, "findings": 8, "questions": 16 } }