Mark

The deploy waits while ==more than 12 pigeons== sit on the roof.

Pineapple pizza needs ==two thirds of the **Friday** vote==.

The office roof holds about 10^3^ pigeons, and the 1^st^ count of the day is at 9:00.

==text== renders as <mark> and ^text^ as <sup>, both native HTML that your page's styles already cover. Markdown works inside a highlight, and {attributes} work after one.

Two equals signs on each side highlight text. Markdown works inside, and {attributes} work after the closing pair:

The ==deploy freeze== starts at noon.

==Pineapple needs **two thirds**==.

==Do not deploy=={.warning}

A single =, as in a = b, stays text, and so does a == with nothing to close it.

Carets on each side make a superscript, with no spaces inside. Escape a space with a backslash:

10^3^ pigeons, the 1^st^ count, and E = mc^2^.

A ^spaced\ superscript^.

^ right after [, as in a footnote reference [^1], never starts a superscript, so the plugin works beside any footnotes plugin.

~sub~ is left out on purpose. Comark's autoClose escapes a lone ~ before any plugin sees the Markdown (comarkdown/comark#462), and GitHub reads ~text~ as strikethrough, so the same file would mean two things. Write <sub>2</sub> for a subscript, as in H₂O.

The plugin adds no classes and no styles. Browsers draw <mark> with a yellow background. To match your theme:

mark {
  background: color-mix(in oklab, gold 40%, transparent);
  color: inherit;
  border-radius: 2px;
  padding: 0 2px;
}

A class after a highlight styles that one alone: ==Do not deploy=={.warning} renders <mark class="warning">.

A highlight marks the words a reviewer should read first, such as the number that changed or the condition a fix adds. Keep it to a few words per paragraph; a highlighted paragraph is a paragraph nobody skims.

The parser is markdown-it-mark and markdown-it-sup, ported to TypeScript, since neither ships types. Comark drops inline tokens it doesn't know and keeps their text, so the plugin renames mark_open and mark_close to the inline span Comark builds with any tag. Comark already builds sup.

The plugin takes no options. In comarkUi(), mark: false turns it off.

comark-ui brings comark-mark and registers it. To use it alone, install it and register the plugin:

pnpm add comark @comark/html comark-mark

import { parseMarkdown } from "comark";
import mark from "comark-mark";

const document = await parseMarkdown(markdown, {
  plugins: [mark()],
});

It has no components and no styles, because <mark> and <sup> are native HTML. It works with registerDefaultPlugins: false and in streaming parses. Every renderer draws the nodes as they are: mark and sup.