Frontmatter is the YAML block at the top of a Markdown file, fenced by --- lines. SquishMark reads it for a post’s title, date, draft status, and so on. Everything is optional; a file with no frontmatter still renders with the defaults (title Untitled, no date, public).
Posts and pages share many fields but not all; the lists below say which apply where. A field that doesn’t apply to a type is ignored there, so nothing breaks if you leave one in.
Posts
A post is a Markdown file in the posts/ directory. The filename sets the slug and, by convention, the date: name it YYYY-MM-DD-slug.md, like 2026-07-04-hello-world.md, and it serves at /posts/hello-world. If you also set date in the frontmatter, that wins.
A realistic post:
---
title: Three nights on the Wonderland Trail
date: 2026-07-04
tags: [trip-report, rainier]
description: Ninety-three miles, one bear, zero dry socks.
author: Sam Ashby
image: /static/user/covers/wonderland.jpg
featured: true
featured_order: 1
series: trip-reports
series_order: 4
toc: true
---
# Three nights on the Wonderland Trail
The rest of the post goes here.
Fields SquishMark reads on posts:
title(defaultUntitled): the post title.date(default none): the publish date,YYYY-MM-DD. Sets ordering in listings. If omitted, the engine falls back to the date in the filename.tags(default none): a list of tags, either[a, b]inline or a YAML list.description(default empty): a short summary, used for the post’s metadata and previews.draft(defaultfalse): when true, the post is hidden from listings and only visible to admins. Flip it to false to publish.featured(defaultfalse): marks the post as featured so themes can surface it.featured_order(default none): position among featured posts. Lower comes first.template(default none): a custom template to render this post with, instead of the theme’s default post template.theme(default none): render this one post with a different theme.author(default none): overrides the site-wide author for this post.image(default none): a featured image URL, also used as theog:imagefor social previews.toc(defaulttrue): whether to show the auto-generated table of contents. Setfalseto turn it off. Posts only; pages never render a TOC.series(default none): a series name, to group related posts into a collection.series_order(default none): position within the series. Lower comes first.
Pages
A page is a Markdown file in the pages/ directory. Pages serve at the root, so pages/about.md is at /about. Subdirectories work too: pages/docs/setup.md serves at /docs/setup. Pages aren’t dated the way posts are, and they don’t get tags, drafts, a TOC, or series.
A realistic page:
---
title: Setup
description: Getting a SquishMark site running.
nav_order: 2
visibility: public
---
# Setup
The rest of the page goes here.
Fields SquishMark reads on pages:
title(defaultUntitled): the page title.description(default empty): a short summary, used for metadata.template(default none): a custom template to render this page with.theme(default none): render this one page with a different theme.image(default none): a featured image URL, also used asog:image.featured(defaultfalse) andfeatured_order(default none): rarely needed on pages, but read the same way as on posts.nav_order(default none): position in the navbar. Pages with anav_ordercome first, in ascending order; the rest follow alphabetically by title. Pages only.visibility(defaultpublic): who can see the page and where it shows up. See below.
Visibility
visibility takes one of three values and controls how a page is exposed. It’s a page field; posts use draft.
public: the normal case. Reachable at its URL, listed in the navbar, and included in the sitemap.unlisted: works at its URL for anyone with the link, but stays out of the navbar and sitemap. Good for pages you link to directly but don’t want in the nav.hidden: returns a 404 to everyone. Use it to park a draft in the repo without publishing.