# The standards family

*Foundations · lesson 5 of 5 · ~10 min*

## What you will learn

How the 90 documents organize into one house with eight rooms, what is normative versus informative, and where to go next depending on who you are.

## One house, eight rooms

The specification repository is organized by question, not by file type:

| Room | The question it answers |
|------|-------------------------|
| `00-foundation` | Why does this exist, and what do words mean? |
| `01-constitution` | What laws can never be broken? (MUC: 6 chapters, 21+ articles) |
| `02-architecture` | How is a meta-model built, laid out, walked, mastered, versioned, validated? (MMAS) |
| `03-federation` | How do sovereign universes interoperate? (MUFP) |
| `04-core-concepts` | What exactly is a Universe, Object, Event, Contract...? |
| `05-reference-architecture` | How do I apply it well (patterns, anti-patterns, the stack)? |
| `06-ecosystem` | How does it live in the world (registries, 1180 external standards, case studies)? |
| `07-guides` | How do I start, as a human or as an agent? |

Around the rooms live the machine artifacts: `schemas/` (JSON Schemas for the interchange format), `tools/` (fingerprint, validate, index generators), `tests/` (the semantic test kit), `examples/` (from minimal-person to a full federation transcript), and three indexes: `spec-index.yaml` (every document), `REQUIREMENTS-INDEX.md` (every requirement, 1284 of them, individually addressable), `llms.txt` (the AI entry point).

## Normative vs informative

Every document declares its class in its header. **Normative** documents contain RFC 2119 requirements (SHALL, SHOULD, MAY), each extracted into the requirements index with a stable ID: conformance means satisfying these. **Informative** documents (guides, case studies, this course) explain and illustrate; they can never override a normative statement. When in doubt: `Terminology.md` and the Constitution win over any prose.

## The three-letter stack

Three acronyms carry most conversations:

- **MUC**: the Meta-Universe Constitution. The invariant layer: sovereignty, identity, events, contracts, conformance.
- **MMAS**: the Meta-Model Architecture Standard. Everything about building models: core architecture, packaging, versioning, naming, validation V0-V5, composition, the lossless-traversal contract (ARCH-017) and data mastership (ARCH-018).
- **MUFP**: the Meta-Universe Federation Protocol. Discovery, identity binding, mapping, contracts, synchronization, trust, conflict resolution, and the wire-level message protocol.

## The ecosystem around the spec

The standard does not live alone. **AISMM** (a stable domain meta-model for describing a software product in full context) is its flagship application; two production models conform end-to-end; a registry of **1180 external standards** (from schema.org to FHIR to ISO 20022) is catalogued with composition rules, so models assemble from the world's existing vocabularies instead of reinventing them. Two case studies document the range: a production software ecosystem, and an entire polity modelled as one Dimension.

## Where to next

- **Continue the courses**: [Building a meta-model](../02-builder/01-anatomy.md) makes you a practitioner; [Vercy for AI agents](../03-agents/01-reading.md) makes your agents safe collaborators.
- **Read the connected overview**: [Overview: the whole standard](/spec/#00-foundation/Overview.md) is this lesson's grown-up sibling.
- **Skim the constitution**: [MUC](/spec/#01-constitution/Meta-Universe-Constitution.md), it is shorter than you fear.

## Key takeaways

- Eight rooms, each answering one question; machine artifacts around them.
- Normative beats informative, always; requirements are individually addressable.
- MUC (laws) + MMAS (building) + MUFP (federating) is the working vocabulary of the whole field.