{"schema":"https://ver.cy/schemas/card/1.0.0","id":"vr.tr.compact-disc","code":"thing-q34467","url":"https://ver.cy/models/thing/q34467/","name":"compact disc","alternateNames":["5 × CD","6 × CD","Compact Disc Digital Audio","5.1 Music Disc","Mini CD","cDVD","audiobook CD","Compressed audio optical disc","High Definition Compatible Digital","CD-MO","CD-RW","gold compact disc"],"kind":"thing","status":"published","version":"0.2.0-wave.5","language":"en","classifiers":{"family":"Thing Registry","category":"Physical world and living systems","entryKind":"thing","plane":"PHY","domain":["PHY.OBJ"],"industry":[],"navPath":"","tags":[],"facets":{}},"whatItIs":"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.","purpose":"Let an agent explain the compact disc format, its variants, specifications and preservation, from standards and archival sources.","scope":{"in":[],"out":[],"boundaries":[]},"distinguishingFeatures":["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."],"structure":{"bundles":[{"id":"disc","name":"Disc","description":"Which disc.","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.","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.","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.","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"}]}]}]}]},"agentConduct":{"may":["explain formats and preservation"],"mustNot":["help circumvent copy protection unlawfully"],"requiresHuman":[]},"ethics":{"considerations":["copyright","digital preservation"],"affectedParties":["artists","archives"]},"owners":{"steward":"nobody; a format; the specifications are licensed and standardised","roles":[],"masterSystems":[]},"relations":[{"target":"Q1048236","type":"parent","note":"registry parent class"},{"target":"Q117208271","type":"parent","note":"registry parent class"},{"target":"Q234870","type":"parent","note":"registry parent class"},{"target":"Q354004","type":"parent","note":"registry parent class"},{"target":"Q66221","type":"parent","note":"registry parent class"},{"target":"optical disc","type":"related","note":"storage medium"},{"target":"DVD","type":"related","note":"format"},{"target":"Super Audio CD","type":"related","note":"distinct format; hybrids carry a CD layer"},{"target":"laser","type":"related","note":"reading technology"}],"interaction":{"identity":{"applicability":"required","items":["Vercy registry: vr.tr.compact-disc","Wikidata: Q34467 (https://www.wikidata.org/wiki/Q34467)","ISRC: 12 characters tracks","UPC/EAN: 12 or 13 digits releases","IFPI SID code: on the disc manufacturing plant"]},"properties":{"applicability":"required","items":["diameter: 120 mm - 80 mm mini CD also exists","thickness and centre hole: 1.2 mm thick, 15 mm hole - nominal","audio format: 44.1 kHz, 16-bit, 2 channels - Red Book"]},"recognition":{"applicability":"required","items":["Iridescent 12 cm disc with the Compact Disc logo","A thin, shiny polycarbonate disc 120 mm across with a central hole, iridescent on the data side."]},"capabilities":{"applicability":"required","items":["explain formats and specifications","explain capacity and audio parameters","explain care and preservation","explain identifiers such as ISRC on CDs"]},"hazards":{"applicability":"required","items":["Disc rot and dye degradation","Scratches causing read errors"]},"interfaces":{"applicability":"required","items":["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)"]},"context":{"applicability":"required","items":["Storing and distributing digital audio and data.","CD-DA (audio)","CD-ROM","CD-R","CD-RW","Mini CD","Video CD","Enhanced CD"]}},"sources":[{"title":"Q34467","url":"https://www.wikidata.org/wiki/Q34467","note":"identity of the registry item, labels and sitelinks"},{"title":"Compact disc","url":"https://en.wikipedia.org/wiki/Compact_disc","note":"general description of the subject"},{"title":"IEC 60908:1999 - Audio recording - Compact disc digital audio system","url":"https://webstore.iec.ch/en/publication/3885","note":"Audio-CD standard scope and issuing body."},{"title":"ECMA-130: Data interchange on read-only 120 mm optical data disks","url":"https://ecma-international.org/publications-and-standards/standards/ecma-130/","note":"CD-ROM dimensions, optical reading, channel coding, error correction and ISO/IEC 10149 correspondence."},{"title":"ISO 18927:2013","url":"https://www.iso.org/standard/62635.html","note":"Withdrawn status and temperature/humidity life-expectancy test scope."},{"title":"Care and Handling of CDs and DVDs: A Guide for Librarians and Archivists","url":"https://nvlpubs.nist.gov/nistpubs/legacy/sp/NISTspecialpublication500-252.pdf","note":"Disc construction, dimensions, dye and phase-change media, degradation and preservation."},{"title":"New Sound Recording Formats - Library of Congress Practice","url":"https://www.loc.gov/catdir/cpso/soundrec.pdf","note":"SACD as a distinct format and the existence of hybrid and non-hybrid SACDs."},{"title":"International Standard Recording Code","url":"https://isrc.ifpi.org/","note":"ISRC has 12 alphanumeric characters and identifies recordings rather than physical discs or releases."}],"openQuestions":["The registry merges multi-disc packages and other formats; they need review."],"resources":{"spec":"/models/things/publications/thing-q34467/spec.json"},"provenance":{"origin":"thing registry research (pass 2)","builtFrom":["models/things/publications/thing-q34467/spec.json"],"providers":["Claude"],"researchStatus":"unreviewed","generatedAt":"2026-10-22T11:44:46Z","builder":"tools/build_cards.py@1.0.0"},"completeness":{"sections":{"classifiers":"filled","whatItIs":"filled","purpose":"filled","distinguishingFeatures":"filled","structure":"filled","agentConduct":"filled","ethics":"filled","owners":"filled","relations":"filled","interaction.identity":"filled","interaction.properties":"filled","interaction.recognition":"filled","interaction.capabilities":"filled","interaction.hazards":"filled","interaction.interfaces":"filled","interaction.context":"filled","sources":"filled"},"notes":{"_gate":"Published through the thing publication gate 1.0 on 2026-10-22T12:05:11+00:00: completeness 1.00; sense: Wikidata description; 7 live sources; review by codex: pass"},"score":1.0}}