A markdown twin is a plain-text or markdown copy of an HTML page served at a parallel URL, so retrieval systems can ingest the content without an HTML parser.
A markdown twin is a plain-text or markdown copy of an HTML page served at a parallel URL — typically {url}.md — so retrieval systems can ingest the content without an HTML parser.
The pattern is aligned with the llms.txt proposal and is common practice on AEO-oriented sites in 2026.
Markdown twins are plain-text or markdown copies of an HTML page served at a parallel URL (typically {url}.md) so retrieval systems can ingest the content without an HTML parser — a practical convention endorsed by the llms.txt proposal but not yet formally consumed by any major answer engine.
llms.txt is a proposed plain-text file at a site's root that lists the URLs and short descriptions a site owner wants LLMs to prioritize when summarizing that site — and as of mid-2026 no major answer engine has confirmed that it uses the file for retrieval or citation.
License content for AI citation by publishing an explicit license that permits quoted citation with attribution and prohibits wholesale republication — the goal is to make it legally safe for models to quote you while keeping copyright leverage against sites that copy the full text.