12 Jun 2024

How To Write YAML Front Matter

A practical guide to the small YAML block that controls title, date, tags, permalink, and visibility in Jekyll posts.

yaml front-matter jekyll documentation

Front matter is the YAML block at the top of a Jekyll page or post. It is written between two lines of three dashes.

Use front matter for individual pages and posts. Use _data files for reusable site lists such as About details, Ref resources, header icons, and share icons.

Basic Post Front Matter

---
title: "My Lecture Note"
summary: "A short one-line description for cards, search, and previews."
date: 2026-06-13 10:00:00 +0530
categories: lecture
tags:
  - quantum
  - notes
  - msc
permalink: /my-lecture-note/
---

What Each Field Does

| Field | Purpose | |—|—| | title | Main title shown on the page and post card | | summary | Short description shown in lists and previews | | date | Publication date and ordering | | categories | Broad grouping and automatic placement on the Notes page | | tags | Searchable labels such as latex, quiz, msc | | permalink | Clean URL for the page | Math rendering is already enabled for posts in _config.yml, so math: true does not need to be repeated in individual posts.

Page Front Matter

Pages outside _posts usually need a layout and permalink:

---
layout: default
title: "Notes"
permalink: /notes/
---

Hidden Template Posts

For material pages that should be linked from Notes but not shown in the main blog list, add hidden: true.

---
title: "M.Sc Sem-I Material Template"
summary: "Template page for M.Sc Semester-I lecture files."
date: 2026-06-13 00:40:00 +0530
categories:
  - notes
  - msc
  - msc-i
tags:
  - msc
  - semester
  - template
permalink: /msc-sem-i-template/
hidden: true
---

Notes Page Categories

The Notes page is automatic. Put the correct category in front matter and the post appears in the right collapsible block.

categories:
  - notes
  - bsc
  - bsc-v

categories:
  - notes
  - msc
  - msc-ii

Exam posts use subject categories:

categories:
  - exam
  - exam-quantum

Documentation posts use documentation categories:

categories:
  - doc-jekyll

Common automatic categories are:

• bsc-i to bsc-viii
• msc-i to msc-iv
• exam-misc, exam-mathematical, exam-classical, exam-quantum, exam-electromagnetic, exam-thermodynamic, exam-statistical, exam-atomic, exam-nuclear, exam-particle, exam-condensed, exam-electronics, exam-experimental, exam-optics, exam-relativity, exam-waves
• doc-jekyll, doc-tech, doc-code

Small Rules

• Keep title and summary in quotes when they contain punctuation.
• Use lowercase tags such as front-matter, latex, and quiz.
• Use category names exactly; category spelling controls automatic grouping.
• Use a trailing slash in permalink, for example /notes/.
• Do not repeat math: true in posts; the site default already enables it.
• Use hidden: true only for pages that should not appear in normal archives.
• For reusable structured lists, edit _data instead of adding front matter fields.