Callouts & Asides
Callouts are the marginalia of this codex: small plates that interrupt the prose to note, advise, warn, or forbid. They are opt-in HTML blocks so plain Markdown stays plain.
The Four Plates
Note — A note records a fact the reader should carry forward. It uses the scribe’s quill and a cool blue wash.
Tip — A tip lights a shortcut. Green wash, candle icon, and ideally one sentence long.
Warning — A warning marks a place where agents have burned themselves before. Amber wash. If you write more than three sentences here, it should be a chapter instead.
Danger — A danger plate is reserved for the irreversible: deleted data, force-pushes, production credentials. Crimson wash, a thicker rule, an open flame. If the reader can undo it, it is only a warning.
Margin Asides
An aside (<div class="aside-note">) is for commentary that enriches but never interrupts: an etymology, a cross-reference, a wry remark. The main argument must survive with the margin torn off. This paragraph flows around the note the way body text shares a page with marginalia in a medieval manuscript — and in print, the float is preserved.
<div class="aside-note">
<span class="kicker">in the margin</span>
The note itself, one or two sentences.
</div>
Authoring Syntax
Callouts are authored as raw HTML with blank lines around the Markdown body, so mdBook still renders the inner content. The second class picks the plate: note, tip, warn, or danger.
<div class="callout warn">
**Warning** — Snap-confined Chromium cannot print to `/tmp`.
</div>
Note — Markdown inside the plate keeps working: italics, code, and even lists:
- first
- second