Common OKF validation errors

Error table

Fix errors in the right order

1. Fix fatal parsing errors first, because field checks depend on readable frontmatter.
2. Add the required type field before tuning optional metadata.
3. Repair tags, resource, title, and description warnings so previews and indexes stay useful.
4. Use the OKF Folder Validator after single-file errors are fixed.
5. Review duplicate resources, broken relative links, and stale timestamps before publishing.

Missing simple frontmatter

OKF files need metadata at the top of the Markdown file. If the file starts directly with a heading, the validator cannot read fields such as type, title, tags, or resource.

---
type: Website Page
title: Contact Page
description: Summarizes the public contact options and support boundaries.
resource: https://openknowledgeformat.online/sample/contact/
tags: [website, support, contact]
timestamp: 2026-06-21T00:00:00Z
---

# Contact Page

Write the reviewed page summary here.

Missing type

The type field tells readers and tools what kind of concept the file describes. Without it, a website page, API endpoint, metric, support playbook, or agent context file all look the same.

• Use short human-readable labels.
• Do not use a file name as the type.
• Keep similar files consistent across the bundle.

Invalid frontmatter

This guide profile uses a simple frontmatter subset. Each normal field should fit the field: value pattern so the browser validator can read it.

Tags not array

Tags are easier to scan and filter when they use a predictable list shape. This site expects inline arrays for the guide profile.

tags: [okf, validator, markdown]

Missing resource

The resource field should point to the page, API reference, data asset, or stable identifier the OKF file describes. This makes source review and stale-content checks possible.

• Use canonical public URLs when possible.
• Use stable internal identifiers for private assets.
• Do not point every file to the homepage.

Broken internal link

Relative Markdown links are useful inside bundles, but single-file paste validation cannot prove that the target file exists. Use folder validation for this check.

1. Open the OKF Folder Validator.
2. Select the local folder that contains the Markdown files.
3. Review unresolved relative links in the validation output.
4. Fix paths or add missing target files.

Link and resource errors

• Duplicate resources usually mean two files describe the same source.
• Broken relative links mean the target file is missing, renamed, or outside the selected bundle.
• Use the OKF Folder Validator to check both cases together.

Folder structure errors

• A missing index.md weakens bundle discovery.
• A bundle with no Markdown files has no useful OKF content to validate.
• Keep generated drafts out of published folders until a source owner reviews them.

Wrong timestamp format

Use a machine-readable timestamp so reviewers can identify freshness. This site uses ISO-style timestamps such as 2026-06-21T00:00:00Z in examples.

Validation is not fact-checking

• It cannot prove that a claim is true or current.
• It cannot certify official Google or OKF compliance.
• It cannot replace OpenAPI schema validation.
• It cannot approve legal, privacy, policy, or security-sensitive text.

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