# What the Markdown digest proves

`markdown_sha256` identifies the extracted Markdown bytes. It is useful for recognizing whether two saved copies contain the same text; it is not a judgment about the web page's truth or completeness.

## Text identity is narrower than provenance

The result associates the digest with `markdown`. Changing a character, newline or encoding can change the bytes and therefore the digest. A rewrapped or edited document should not retain the original digest as a claim that its text is unchanged.

The digest does not establish who authored the source, whether the final URL is the one you intended, whether important content was omitted, or whether a quoted claim is correct. Keep `requested_url`, `url`, title, warnings and truncation alongside it. The original operation ID identifies the attempt; the digest identifies its Markdown, not the account's authority to extract.

## Use the value carefully

When preserving an existing result, retain the exact Markdown and original metadata separately from your edited notes. If you compare local hashes, calculate them over the original text bytes, not a rendered view or JSON wrapper. A matching digest supports byte identity only. A mismatch is a reason to check export formatting or edits before alleging a changed source.

For source confidence, inspect the [URLs, headings and links](/docs/zilch/inspect-source-urls-headings-and-links) and the source itself. For partial output, read [warnings and truncation](/docs/zilch/read-truncation-and-extraction-warnings). No digest replaces those checks.