Obsidian YAML Frontmatter

YAML Frontmatter Management

Standardize YAML frontmatter properties across all vault content.

When to Use This Skill

Activate when you need to:

• Add or update frontmatter in markdown files
• Ensure consistent property naming and formatting
• Format tags, dates, or other property values
• Validate frontmatter structure

Note: This skill manages frontmatter PROPERTIES (keys, values, types, formatting). For document STRUCTURE (heading hierarchy, section order, frontmatter position), use obsidian-markdown-structure skill.

Core Frontmatter Rules

1. Single YAML Block at Top

Structure:

---
property: value
---

## First Section Header

Critical Rules:

• One YAML block at top of file
• Blank line after closing ---
• No content before first heading (after frontmatter)

2. Standard Property Names

Use lowercase, consistent keys:

✅ CORRECT:
title: Document Title
created: 2025-10-31
tags:
  - tag1
source: https://example.com
author: Author Name

❌ INCORRECT:
Title: Document Title (capitalized)
date: 2025-10-31 (use "created" not "date")
tag: tag1 (use "tags" plural)

No Duplicate Properties:

• Use created (not both date and created)
• Use tags (not both tag and tags)

3. Tag Formatting

CRITICAL: Plain text in YAML, NO hashtags:

✅ CORRECT:
tags:
  - journal
  - daily
  - reflection

❌ INCORRECT:
tags:
  - #journal
  - #daily

Always use list format with dashes:

✅ CORRECT (list format):
tags:
  - tag1
  - tag2

❌ INCORRECT (inline):
tags: [tag1, tag2]

4. Date Format

Use YYYY-MM-DD consistently:

✅ CORRECT:
created: 2025-10-31
updated: 2025-11-01

❌ INCORRECT:
created: 10/31/2025
created: 2025-10-31T10:30:00

5. Link Lists

Wrap wiki links in quotes:

✅ CORRECT:
sources:
  - "[[Lifelog/2025-10-31 Lifelog - Codex]]"
  - "[[Limitless/2025-10-31]]"

links:
  - "[[Roundup/2025-10-31]]"

attendees:
  - "[[진영]]"
  - 민성

❌ INCORRECT:
sources:
  - [[Lifelog/2025-10-31 Lifelog - Codex]] (missing quotes)

6. Quote Values with Special Characters

Quote values containing: : # " or numeric-looking strings

Single quote wrapping (easiest for values with "):

✅ CORRECT:
title: 'He said, "Hello."'
note: 'It's called "PKM".'

Double quote wrapping with escaping:

✅ CORRECT:
title: "He said, \"Hello.\""
source: "https://example.com"
version: "2.0"

Literal double-quote character:

✅ CORRECT:
quote_char: '"'

Mixed quotes preference: Use double quotes, escape only " (single quotes don't need escaping):

✅ CORRECT:
note: "It's called \"PKM\"."

❌ INCORRECT:
title: AI Era: Thriving Framework (unquoted colon)
version: 2.0 (parsed as number, not string)

Multiline values (no escaping needed):

✅ CORRECT:
description: |
  He said, "Hello."
  New line preserved.

Standard Property Set

Core Properties (All Content)

---
title: Document Title
created: YYYY-MM-DD
tags:
  - category
  - type
---

Content with Sources

---
title: Article Title
created: YYYY-MM-DD
source: https://url or file path
author: Author Name
tags:
  - clipping
  - topic
---

Relational Content

---
title: Document Title
created: YYYY-MM-DD
tags:
  - category
sources:
  - "[[Source File 1]]"
  - "[[Source File 2]]"
links:
  - "[[Related Topic]]"
---

Events/Meetings

---
title: Meeting Name
created: YYYY-MM-DD
event_date: YYYY-MM-DD
attendees:
  - "[[Person 1]]"
  - Person 2
sources:
  - "[[Limitless/YYYY-MM-DD#Section]]"
tags:
  - meeting
  - event
---

Workflow

Step 1: Determine Content Type

• Daily content (Journal, Lifelog, Roundup)
• Ingested content (Clippings, Articles)
• Created content (Analysis, Tasks, Events)
• Topic/Project pages

Step 2: Select Property Set

• Core properties (title, created, tags)
• Add source/author if applicable
• Add relational links (sources, links, attendees)
• Add content-specific properties

Step 3: Format Values

• Dates: YYYY-MM-DD format
• Tags: Plain text list (no #)
• Links: Quoted wiki links
• Special chars: Quote values with : or #

Step 4: Structure Check

• Single YAML block at top
• Blank line after ---
• Consistent property names (lowercase)
• No duplicate properties

Reference Documentation

For detailed property definitions and examples:

• reference/standard-properties.md - All property definitions
• reference/examples.md - Frontmatter by content type

Quality Checklist

Before completing frontmatter:

• Single YAML block at top with blank line after
• All property keys lowercase and consistent
• Tags are plain text (NO hashtags)
• Dates in YYYY-MM-DD format
• Wiki links wrapped in quotes
• Special characters quoted appropriately
• No duplicate properties (created vs date, tags vs tag)