# Redline format > The markdown rendering behind text_url: change elements, attribution, and worked examples. Every ready comparison, merged document, and version history carries a `text_url`: the same redline rendered as markdown with its changes marked inline. It exists so an agent can read the changes directly, instead of unzipping a `.docx` or re-deriving the diff from the source documents. It is working material for analysis, not a deliverable. Hand a person the Word or PDF redline from the download manifest; give the model this. ## The self-describing header Every file opens with the same header. It is an HTML comment, so markdown renderers hide it while anything reading the file as text still sees it — which means an agent that reaches a saved copy, a cached path, or a file from an earlier session can still read it correctly with no other context. ```html ``` ## Change elements | Element | Meaning | | --- | --- | | `` | Text inserted in the revision | | `` | Text deleted from the base version | | `` / `` | The two halves of one relocation, tied by a shared `move-id` | | `` | Competing changes from different revisions over the same text — merged documents only | `author` is who made the change; `revision` is the document version it came from, so in a merged or version-history document every change says which draft introduced it. Text outside a change element is unchanged. On ``, ``, ``, and ``, `id` is the tracked revision's own identifier in the source document — every element corresponds to exactly one revision, and the [JSON rendering](/developers/reference/json-format) reports the same value for the same change, so a change can be cross-referenced between the two. ## Insertions and deletions The most common case: one revision edits a sentence. ```html 6. The Recipient will promptly notify the Company of any unauthorized disclosure of Confidential Information. ``` Elements nest when revisions changed the same text. `kept then cut` is text A inserted that B then partially deleted. ## Moves A relocated clause is one move, not a delete and an unrelated insert. Both halves carry the same `move-id`. ```html 1. As used herein, “Confidential Information” will mean any and all technical and non-technical information … of the Company. 3. As used herein, “Confidential Information” will mean any and all technical and non-technical information … of the Company. ``` ## Multi-author merges In a merged document, non-conflicting changes from different revisions sit side by side, each keeping the revision it came from. ```html … to protect the confidentiality of certain valuable confidential information of the Company … 1. … design details and specifications, engineering, financial information, large language models, procurement requirements, purchasing, manufacturing … ``` ## Conflicts When two revisions edit the same span, every candidate is wrapped in a ``, each keeping its own revision. Surface these to a person; do not resolve them automatically. ```html (d) was rightfully communicated to the Recipient from an individual or entity by a person free of any obligation of confidence … ``` ## Everything else in the document The document's own headings, section numbering, and signature tables are preserved as markdown. Literal square brackets in the text are escaped — `\[Signature Page Follows\]` is document text, not a change. `text_url` is omitted for spreadsheet comparisons and when the rendering is unavailable. The `word_redline` download carries the same set of tracked changes either way.