Glossary
Assurance Level
The confidence dimension of a track's rating, measuring how trustworthy the metadata assessment is. Three levels exist: Collection Ready (self-certified by TrackForge's automated pipeline), Certified (multi-source corroboration plus third-party audit), and Litigation-Grade (human attestation plus blockchain anchor). In v1.0, all tracks are assessed at Collection Ready; higher assurance levels are architecturally defined but not yet operational. See the Rating Methodology for the full assurance axis.
Blockchain Anchor
The permanent record of a Merkle root hash in a blockchain transaction. TrackForge submits the Merkle root to OpenTimestamps calendar servers, which aggregate it into a blockchain transaction. Once confirmed in a block, the anchor is immutable — it cannot be altered or removed. The anchor proves that the Merkle root (and therefore all tracks committed to it) existed at or before the block's timestamp.1
Bronze Tier
Partially enriched metadata meeting minimum certification requirements (ISRC, duration, and at least one of ISWC or identified writer). Bronze tracks have core recording identifiers and at least some compositional data, but gaps remain. Those gaps are documented transparently in the certification. See Certification Tiers.
Canonical JSON
The deterministic, normalised JSON representation of a track's certified metadata. Canonical JSON is produced using strict serialisation rules: sorted keys, no whitespace, ASCII-safe encoding, and removal of null/empty values. Given identical input data, the canonical JSON is always byte-exact, ensuring that the SHA-256 hash is reproducible. See the full specification at Canonical JSON Schema.
Chinese Wall
The architectural separation between TrackForge's enrichment services (which modify catalogue data) and rating services (which independently assess catalogue health). Enforced at three levels: application architecture (pure-function Rating Oracle with zero enrichment imports), database access control (dedicated rating_reader PostgreSQL role with SELECT-only permissions), and transaction isolation (read-only transactions). See Rating Independence for the full technical details.
Collection Confidence Tier
One of four classifications (Tier 1 through Tier 4) indicating how confident TrackForge is that royalties are actually flowing for a track. Tier 1 (Verified Collecting) requires active CMO distribution plus foreign corroboration. Tier 4 (Absent) means no CMO registration was found. Collection confidence is complementary to metadata completeness — a track can have complete metadata but no evidence of active collection, or vice versa. See the Rating Methodology Section 5 for full tier definitions.
Completeness Level
One of six levels (MINIMAL through FORENSIC_GRADE) measuring how thoroughly a track's rights-critical metadata has been verified. Each level has explicit field requirements and minimum source counts. The six levels are grouped into four Certification Tiers for public-facing communication: Gold (GOLDEN+), Silver (VALIDATED), Bronze (OPERATIONAL), Declared (MINIMAL). See the Rating Methodology Section 2.1 for the complete threshold table.
Certification Batch
A set of tracks — typically one catalogue — that are certified together and share a single Merkle tree. All tracks in a batch are hashed, assembled into the tree, and anchored to the blockchain as a unit. The batch is the fundamental unit of blockchain anchoring: one batch produces one Merkle root, which is committed in one blockchain transaction.
Certification Tier
The rating assigned to an individual track based on the depth of independent verification performed on its rights-critical metadata. Four tiers exist: Gold (fully verified with multi-source corroboration), Silver (structurally complete), Bronze (partially enriched with gaps), and Declared (owner-submitted data only, not independently verified). Certification tiers are the track-level building blocks of the Portfolio Grade — they measure different things and operate at different levels of the rating system. See Certification Tiers for the full tier definitions and decision process.
Declared Tier
User-submitted metadata that has been cryptographically timestamped but not independently verified by TrackForge. The only requirement is a valid ISRC. Declared certifications attest that the submitting party declared the metadata at a specific point in time — they do not attest to the accuracy of the declared data. See Certification Tiers.
Golden Record
A track metadata record that meets TrackForge's data completeness requirements for certification. In the Rating Methodology, a "Golden Record" corresponds to Completeness Level 3 (GOLDEN) or higher — tracks with ISRC, ISWC, writer IPI, writer role, validated splits, and at least one PRO registration. The term maps to the Gold Certification Tier in public-facing communication. Tracks at GOLDEN completeness represent the structurally complete core of a catalogue — the tracks where the full rights chain is verified and collection can be confirmed.
Gold Tier
Highest certification level. Track has complete, multi-source-verified metadata with writer ownership shares summing to approximately 100%, corroboration from two or more independent authoritative sources, and documented human operator review and approval. Gold represents the strongest evidentiary standard TrackForge offers. See Certification Tiers.
IPI
Interested Party Information number. A unique numeric identifier assigned to writers and publishers by collecting societies (PROs) worldwide, administered under the CISAC CIS-Net system. IPI numbers are used to unambiguously identify rights holders across territorial boundaries — a writer may be known by different names or spellings in different territories, but their IPI is globally unique.
ISRC
International Standard Recording Code. A 12-character alphanumeric code (e.g. GBAYE0100538) that uniquely identifies a specific sound recording. ISRCs are assigned by national agencies and are the primary identifier used across streaming platforms, collecting societies, and rights databases. Each ISRC identifies a particular recording — not the underlying composition, which is identified by an ISWC.
ISWC
International Standard Musical Work Code. A unique identifier for the underlying musical composition (the "work"), as distinct from any particular recording of it. An ISWC takes the form T-NNN.NNN.NNN-C (e.g. T-010.466.720-3). Multiple recordings (each with their own ISRC) may share the same ISWC if they are performances of the same composition.
Neighbouring Rights
Performance rights in the sound recording (master), as distinct from composition rights in the underlying musical work. Neighbouring rights are administered by separate collecting societies — PPL (UK), GVL (Germany), SoundExchange (US), SCPP/SPPF (France), PPCA (Australia) — and cover broadcast, public performance, and some digital uses. Neighbouring rights registration is separate from composition rights registration (PRS, GEMA, MLC, SACEM) and is often overlooked by catalogue owners. TrackForge assesses neighbouring rights on an advisory basis only — they are not included in the certification grade. See Certification Scope for details.
Merkle Proof (Inclusion Proof)
A compact set of sibling hashes that proves a specific leaf (track hash) belongs to a Merkle tree with a given root hash. The proof is logarithmic in size: for a tree of 1,000 leaves, only 10 hashes are needed. Verification involves replaying the hash chain from the leaf to the root and comparing the result. See the full specification at Merkle Proof Format.
Merkle Root
The single hash at the top of a binary Merkle tree, representing all leaf values in the tree. In TrackForge's system, the Merkle root commits to every certified track in a batch. It is the value anchored to a public blockchain via OpenTimestamps. Changing any single leaf (track hash) would produce a completely different root, making tampering detectable.
Merkle Tree
A binary hash tree in which every leaf node is a hash of data (in TrackForge's case, the SHA-256 of a track's canonical JSON), and every non-leaf node is the hash of its two children. The tree reduces an arbitrary number of hashes to a single root hash, while allowing any individual leaf to prove its inclusion via a compact Merkle proof. See Merkle Proof Format for construction rules.
OpenTimestamps
An open protocol for creating blockchain-backed timestamps without requiring direct interaction with the blockchain network. Timestamp requests are submitted to calendar servers, which aggregate many requests into a single blockchain transaction. The protocol produces self-contained proof files (.ots) that can be verified independently of any server. See OpenTimestamps Integration for TrackForge's implementation.
Portfolio Grade
A catalogue-level letter grade from AAA through D representing the revenue-weighted quality of a catalogue's metadata. Calculated by aggregating individual track Certification Tiers and weighting by each track's revenue contribution. AAA indicates ≥95% of revenue secured by verified metadata; D indicates <1%. A catalogue with 90% of revenue generated by Gold-tier tracks receives a higher portfolio grade than one where 90% of revenue comes from Bronze-tier tracks, even if both catalogues have the same number of tracks at each tier. When no revenue data exists, the grade falls back to track-count weighting. See the Rating Methodology Section 2.3 for the full grade scale.
Process Fidelity
The principle that TrackForge certification attests to the rigour of the verification process, not to absolute legal truth. A certification confirms that a documented, repeatable, multi-source enrichment and validation process was followed and that the metadata was in the stated condition at the stated time. It does not guarantee that no competing claims, errors, or contradictions exist. The depth of the process varies by certification tier. This concept is analogous to title insurance in property law. See Scope & Legal Positioning for the full legal analysis.
Proof Bundle
A self-contained ZIP archive containing all data and cryptographic proofs needed for independent, offline verification of a catalogue's certification. The bundle typically includes: per-track certificates (with canonical JSON, record hashes, and Merkle proofs), the batch metadata, the OpenTimestamps .ots proof file, and verification instructions. With this bundle, any third party can verify the certification without contacting TrackForge.
Re-Certification
The process of issuing a new certification version when a track's metadata changes after initial certification. The new certification is cryptographically linked to its predecessor by including the previous record hash, forming a version chain. Re-certification creates a new leaf in a new Merkle tree — it does not alter or invalidate the original certification, which remains a valid record of the metadata at that earlier point in time.
SHA-256
Secure Hash Algorithm 256-bit. A cryptographic hash function that produces a fixed-size 256-bit (64 hexadecimal character) digest from arbitrary input data. SHA-256 is a one-way function: given a hash, it is computationally infeasible to determine the original input. TrackForge uses SHA-256 at every level of the certification system — hashing canonical JSON into record hashes, combining sibling hashes in the Merkle tree, and producing the Merkle root submitted to the blockchain.
Silver Tier
Structurally complete composition rights metadata with verified writer identities (IPIs). Requires ISRC, ISWC, duration, and at least one writer with a verified name and IPI number. Equivalent to the original Golden Record standard from Methodology Version 1.0. Silver represents strong automated verification of composition rights without dedicated human review. Neighbouring rights (sound recording CMO registration) are assessed separately on an advisory basis. See Certification Tiers.
Tier Promotion
The process of re-certifying a track at a higher tier after additional data or verification becomes available. For example, a Bronze track may be promoted to Silver when a missing ISWC or writer IPI is obtained, or a Silver track may be promoted to Gold after complete share data is provided and human review is performed. Promotion creates a new certification linked cryptographically to the previous one. See Certification Tiers.
Version Chain
The cryptographic linked list of certification versions for a track. When a track is re-certified, the new certification references the previous certification's record hash, creating an immutable chain of provenance. Each link in the chain is a separate, independently verifiable certification anchored to its own Merkle tree and blockchain timestamp. The version chain provides a complete audit history of how a track's certified metadata has evolved over time.