diff --git a/skills/daybook-posting/SKILL.md b/skills/daybook-posting/SKILL.md
index bc5aa6b..17f6b60 100644
--- a/skills/daybook-posting/SKILL.md
+++ b/skills/daybook-posting/SKILL.md
@@ -71,6 +71,24 @@ Tailwind's in-browser compiler) without internet access. If the deployment
 target is offline, don't reach for these — use `markdown`/`html_fragment`
 instead, which are styled entirely server-side with no external requests.
 
+**Self-hosted alternative for tables/JSON — no CDN needed:** Daybook already
+vendors Grid.js and renderjson locally (used to render `csv`/`json`
+artifacts), and they're reachable as plain static files from any artifact,
+including `html_full`:
+
+```html
+<link rel="stylesheet" href="/static/vendor/gridjs/mermaid.min.css">
+<script src="/static/vendor/gridjs/gridjs.umd.js"></script>
+<!-- or, for a collapsible JSON tree: -->
+<script src="/static/vendor/renderjson/renderjson.js"></script>
+```
+
+Prefer these over an external CDN for table/JSON rendering inside a custom
+`html_full` page — same libraries, but self-hosted, so they work offline
+and don't depend on a third party staying up. This only covers
+tables/JSON; there's no vendored equivalent for Tailwind/Chart.js, so the
+CDN snippets above are still the only option for those.
+
 Only use this for `html_full` specifically — never add CDN references to
 `markdown`/`html_fragment`/`deck`. Those kinds exist so Daybook, not the
 poster, owns styling; injecting a default CDN habit into them would