Frontmatter

Frontmatter is a YAML mapping between two --- lines at the top of a concept file.

Core metadata

type: Metric
title: Revenue
description: Recognized company revenue.
resource: https://example.com/revenue
tags:
  - finance

Provenance

sources:
  - id: docs
    resource: https://example.com/docs
    title: Documentation
    author: Jane Doe
    usage_count: 3
    last_modified: "2026-01-01"
    usage_window: P30D

See Sources & provenance for how these connect to footnotes in the body.

Generation

generated:
  by: my-generator/1.0
  at: "2026-01-01T00:00:00Z"

Verification

verified:
  - by: human:ramesh
    at: "2026-01-02T00:00:00Z"

Official OKF specification requirement

Both the array form above and the bare-mapping form (verified: {by, at}) are valid. Tools must accept both and may normalize internally, but should preserve whichever form is valid on serialization.

Lifecycle

status: draft   # draft | stable | deprecated
stale_after: "2026-12-31"

Official OKF specification requirement

An omitted status is treated as stable.

Unknown fields

Any producer-defined field not listed here is preserved as-is. The Concept Editor includes a generic key/value editor for exactly this case.