Codes, Cataloging, and Versioning

3.1 Code Grammar: STREAM-TYPE-LEVELSEQ

Purpose: create human-readable, machine-valid IDs that never change.
Canonical pattern (regex):
^(CORE|HLT|PUB|FIN|POL|TEC|ENV|SYS)-(NB|MB|MC)-[0-6][0-9]{2}$

• STREAM: CORE, HLT, PUB, FIN, POL, TEC, ENV, SYS
• TYPE: NB (Nanobadge, 2–4h) · MB (6–8h) · MC (12–20h)
• LEVEL: 0–6 → 0 Orientation · 1 Foundations · 2 Methods · 3 Practitioner · 4 Specialist · 5 Capstone Unit · 6 Research
• SEQ (two digits): 01–99 within each LEVEL

Immutable: Codes never embed versions and are never reused.

3.2 Streams & Controlled Vocabularies (CORE, HLT, PUB, FIN, POL, TEC, ENV, SYS)

• CORE (shared governance, evidence, EO/GIS, EWS/AAP/DSS)
• HLT (One-Health, epidemiology, health systems)
• PUB (civil protection, cities, infrastructure, procurement)
• FIN (market/credit/liquidity, model risk, climate/ESG, parametrics)
• POL (geopolitics, sanctions, civic space, information integrity)
• TEC (cyber, privacy, AI, OT/ICS)
• ENV (climate, nature/biodiversity, adaptation, water/land/air)
• SYS (complexity, systemic risk, foresight, red-teaming)

Vocabulary control: streams, types, levels, standards tags, competencies, languages, and assessment types use closed lists for clean analytics and interoperability.

3.3 Levels & Ranges (0–6) and Reserved Sequences

• Level semantics: 0 Orientation; 1 Foundations; 2 Methods/Tools; 3 Practitioner; 4 Specialist; 5 Capstone Unit; 6 Research.
• Sequence policy (per level):
  • 01–29 Core set (common across audiences)
  • 30–69 Track A (e.g., FIN—ALM & Liquidity; ENV—Adaptation)
  • 70–89 Track B (parallel specialization)
  • 90–99 Reserved (emergency use, migrations, sunset placeholders)
• Do not encode language/region in codes (handled via metadata/i18n).

3.4 Program Codes: PRG-[TIER]-[STREAM|PATH]-NN

Pattern (regex): ^PRG-(PC|AC|DIP|FEL)-([A-Z][A-Za-z-]+)-[0-9]{2}$

• TIER: PC Professional · AC Advanced · DIP Diploma · FEL Fellowship
• STREAM|PATH: a stream (e.g., FIN) or named pathway (Climate-Finance)
• NN: 01–99 sequence
• Programs are separate objects listing required courses (with minimum accepted revisions) plus a capstone.

3.5 Permalinks & Slugs (Latest vs Specific rev)

• Course (latest): /academy/courses/FIN-MC-318
• Specific revision: /academy/courses/FIN-MC-318?rev=25.09.1
• Program: /academy/programs/PRG-PC-FIN-01
• Redirects: Any legacy -vYY.MM URLs 301 to the stable slug; ?rev= preserved.
• Canonical tags: course pages publish canonical to the stable URL.

3.6 Semantic Versioning: Major/Minor/Patch Rules

Format: rev: YY.MM.P → Year, Month, Patch.

• MAJOR (YY bump): Learning outcomes change or assessment blueprint shifts.
  Effect: invite delta exam for renewal; program minimum revs may increase.
• MINOR (MM bump): New labs, datasets, or examples; outcomes unchanged.
  Effect: no renewal required.
• PATCH (.P): Editorial fixes, typos, figure clarifications.
  Effect: no assessment impact.

Rule of thumb: If a learner’s previously demonstrated competence would be assessed differently, it’s MAJOR.

3.7 Deprecation, Supersession & Redirect Policy

• Status values:active | deprecated | superseded.
  • Deprecated: new enrollments discouraged; page shows successor mapping; valid for transcripts.
  • Superseded: replaced by a new code (rare; used for structural splits/merges).
• Sunset cadence: deprecated → review at 12 months; superseded → block enroll, transcript remains valid.
• Redirects: legacy slugs 301 to stable; superseded codes display banner with successor link.
• Transcripts: always record code + rev at time of completion; never altered.

3.8 SKU vs Academic Code Separation

• Academic code (e.g., FIN-MC-318) identifies learning; SKU identifies a sellable product/bundle.
• Many-to-one mapping allowed (cohorts, languages, support tiers).
• Do not encode pricing, dates, or cohort info in academic codes.
• Example: SKU: FIN-MC-318-EN-COHORT-2025Q1 → maps to FIN-MC-318.

3.9 Catalog Linter & Acceptance Checks

CLI: nexus-catalog-lint <path-to-json>
Validations (must-pass):

1. Regex checks for course/program codes; no embedded version in codes.
2. Uniqueness of codes, slugs, and SKUs.
3. Prereq grammar parses; no DAG cycles; at least one valid path with/without RPL.
4. Program requires only existing course codes and specify min revs.
5. Metadata completeness: hours, NCU, outcomes (3–6), standards tags, competency maps, nx_links, accessibility flags.
6. i18n fields: languages array present; alt text/captions flags for A/V.
7. Cross-listing: canonical owner set; mirror streams listed.
8. Status logic: deprecated/superseded entries have successor mapping.
9. Permalinks: stable slug exists; legacy redirect defined (if applicable).
10. QA hooks present: psychometrics keys for graded units; last standard-setting date.

Exit codes: 0 OK · 1 WARN (non-blocking) · 2 FAIL (block publish).

3.10 Sample Mappings: Before/After Refactor

Result: With this scheme, Nexus codes remain stable, pages are discoverable, programs are composable, and revisions are auditable—supporting lifelong learning, employer verification, and global interoperability.