# RFC-0004: Vocabulary

**Status:** Proposed
**Phase:** The Bedrock Phase

## Abstract

This RFC formalizes Open Engineer's core vocabulary as a defined, versioned glossary with one authoritative location.

## Motivation

Engineers across disciplines share an informal conceptual vocabulary. Without formal definitions, terms are used inconsistently, leading to ambiguity. A standard requires precise, non-redundant terminology.

## Observation

During development, the same concept was sometimes described with different words in different documents, creating the potential for silent divergence.

## Engineering Principle

Every canonical term has one definition, located in one authoritative document (OE-0002). All other documents reference OE-0002; they do not redefine terms.

## Reasoning

A shared vocabulary is the foundation of a shared standard. Formal definitions eliminate ambiguity and create a reliable foundation for all subsequent work.

## Relationship to Existing Concepts

Vocabulary is defined in OE-0002. Term consistency is enforced by the No Duplication editorial principle (`reference/editorial-principles.md`, Section 7) and the Enduring Concept test (Section 5).