Description
MMD metadata keys (CSS:, HTML Header:, Copyright:, etc.) correctly
formatted at the top of a document are completely absent from exported HTML.
Marked rebuilds <head> from scratch on export using its own template,
discarding all MMD metadata that MMD would normally inject.
Steps to Reproduce
- Create a Markdown file with MMD metadata at the very top:
CSS: file:///Users/username/path/to/style.css
Copyright: Copyright © 2026 Author Name. All rights reserved.
HTML Header: <meta name="author" content="Author Name">
# Document Title
- Open in Marked 3 with MultiMarkdown processor
- Export as HTML (⌘S) with "Include style in output" checked
- Inspect the exported HTML
<head>
Expected Behavior
CSS:should generate a<link rel="stylesheet">tag in<head>HTML Header:should inject raw HTML into<head>Copyright:should appear as<meta name="copyright">in<head>
Actual Behavior
All metadata keys are completely absent from the exported HTML. The <head>
contains only Marked's own template (charset, viewport, title, selected style).
Documentation Reference
The Marked 3 Exporting docs state:
"You can, however, use the HTML Header metadata to include your own
stylesheet."
— https://markedapp.com/help/Exporting.html
The MultiMarkdown v5 User's Guide documents the CSS: key:
"This metadata specifies a URL to be used as a CSS file for the produced
document."
— https://fletcher.github.io/MultiMarkdown-5/MMD_Users_Guide.pdf (p.28)
The MultiMarkdown v5 User's Guide documents HTML Header::
"You can include raw HTML information to be included in the header.
MultiMarkdown doesn't perform any validation on this data — it just copies
it as is."
— https://fletcher.github.io/MultiMarkdown-5/MMD_Users_Guide.pdf (p.28)
Copyright: Copyright © 2026 Yishai Binyamin. All rights reserved.
Exported HTML <head> — no trace of copyright, no <meta> tag, nothing.
