An updated note says what changed, and where the old one is

CONTRIBUTING.md

@@ -236,6 +236,12 @@ something works, not how hard it was to make work.
   the reason to write *that* note, not to reference it from this one. Say the
   general thing the reader can check, and leave the specific one to its own
   note.
+- **An updated note carries a `## History` section**, and only versions that
+  were deposited appear in it: a version, a date, the version DOI, what changed
+  and — when it applies — what did not. A published note is never changed
+  silently. The live page shows the current history and each deposited PDF
+  shows the history up to its own version, so nothing goes back to amend an
+  older PDF. See PUBLISHING.md.
 - **Every figure and table ships the script that made it**, in the note's
   `examples/`. A number a reader cannot regenerate is an assertion.
 - **Alt text describes what the image shows, including the numbers.** It is read

PUBLISHING.md

@@ -58,6 +58,39 @@ updates to a published article affect only the private copy until an explicit
 publish. That matches the brief: cosmetic web corrections need no deposit, and
 a substantive change is a new version.
 
+### The History section
+
+An updated note says so, in a `## History` section at the end. Never change a
+published note silently: that is the one thing every correction policy agrees
+on, because a reader who has the old text has no way to know it moved.
+
+Each entry is a version, a date, the version DOI, and a sentence on what
+changed:
+
+```markdown
+## History
+
+- **1.1.0** — 2026-09-08 · [10.6084/m9.figshare.33216996.v2](https://doi.org/10.6084/m9.figshare.33216996.v2)
+  Rewritten for the new time-stepping interface: `foo()` replaces `bar()`.
+  The method and the results are unchanged.
+- **1.0.0** — 2026-08-11 · [10.6084/m9.figshare.33216996.v1](https://doi.org/10.6084/m9.figshare.33216996.v1)
+  First published.
+```
+
+**Say what did NOT change.** When an API moved and the physics did not, that
+sentence is what saves a reader from re-reading the note to find out.
+
+**Only deposited versions get an entry.** A typo fix is a patch bump and no
+deposit, so it leaves no trace here; a minor or major bump is a new deposit and
+does. Otherwise the section fills with corrections nobody needs to know about,
+and the ones that matter are lost in them.
+
+**The live page carries the current history; each deposited PDF carries the
+history up to its own version.** That is correct rather than a defect, and it
+is why nothing goes back to amend an older PDF -- a deposited copy is a fixed
+document, and the version DOIs are what connect them. The concept DOI, with no
+`.vN`, always resolves to the newest.
+
 **A superseded guide becomes a new version, not a new article.** This is the
 editorial rule, and it is why the how-tos are deposited at all. The container
 instructions are the case in point: useful to know about, and going out of date.

articles/running-underworld-in-a-browser/metadata.yml

@@ -12,7 +12,7 @@ authors:
     orcid: 0000-0003-3685-174X
     affiliation: Australian National University
 publication_date: 2026-08-11
-version: 1.1.0
+version: 1.1.1
 license: CC-BY-4.0
 canonical_path: /running-underworld-in-a-browser/
 legacy_paths: []

articles/running-underworld-in-a-browser/running-underworld-in-a-browser.md

@@ -26,7 +26,7 @@ exports:
     template: ../../templates/pdf
     output: running-underworld-in-a-browser.pdf
     article_id: UWTN 2026-010
-    article_version: 1.1.0
+    article_version: 1.1.1
 doi: 10.6084/m9.figshare.33216996
 ---
 <div class="uwtn-banner"><img src="figures/banner.jpg" alt=""><div class="uwtn-credit">Photo by <a href="https://unsplash.com/@jbl12761?utm_source=underworld-technical-notes&utm_medium=referral&utm_campaign=api-credit">James Lee</a> / <a href="https://unsplash.com/?utm_source=underworld-technical-notes&utm_medium=referral&utm_campaign=api-credit">Unsplash</a></div></div>
@@ -279,6 +279,16 @@ Three limits come with not running servers:
 
 
 
+## History
+
+- **1.1.0** — 2026-08-31 · [10.6084/m9.figshare.33216996.v2](https://doi.org/10.6084/m9.figshare.33216996.v2)
+  Revised for house style and shortened by about a fifth, and the abstract
+  rewritten to say what the thing is for rather than list its parts. The
+  machinery described is unchanged: the container, the launcher, the workflows
+  and the URL all work exactly as they did in 1.0.0.
+- **1.0.0** — 2026-08-11 · [10.6084/m9.figshare.33216996.v1](https://doi.org/10.6084/m9.figshare.33216996.v1)
+  First published.
+
 <!-- uwtn-acknowledgement -->
 
 <div class="uwtn-discuss"><div class="uwtn-discuss-head">Comments</div><div class="uwtn-discuss-body">Discussion of these notes happens in GitHub Discussions, so it stays with the source and is searchable alongside it.</div><div class="uwtn-discuss-links"><a href="https://github.com/Underworld-Technical-Notes/underworldcode.org/discussions?discussions_q=running-underworld-in-a-browser">Read the discussion</a><a href="https://github.com/Underworld-Technical-Notes/underworldcode.org/discussions/new?category=general&title=running-underworld-in-a-browser">Start one</a></div></div>

templates/article-template/ARTICLE.md

@@ -113,3 +113,16 @@ deposited with the note, so the archived record carries working code.
 When a release breaks one, update it and publish a **new version** of the same
 deposit rather than a new note — the DOI already in circulation then resolves to
 the working notebook.
+
+## History
+
+<!-- Delete this section until the note has been updated after deposit.
+     Then one entry per DEPOSITED version, newest first: version, date,
+     version DOI, what changed, and what did not. A typo fix is a patch
+     bump with no deposit and gets no entry. See PUBLISHING.md.
+
+- **1.1.0** — YYYY-MM-DD · [10.6084/m9.figshare.NNNNN.v2](https://doi.org/10.6084/m9.figshare.NNNNN.v2)
+  What changed, in a sentence. What did not change, if that helps.
+- **1.0.0** — YYYY-MM-DD · [10.6084/m9.figshare.NNNNN.v1](https://doi.org/10.6084/m9.figshare.NNNNN.v1)
+  First published.
+-->

tests/test_migration.py

@@ -2416,3 +2416,40 @@ def test_the_deposit_reminder_asks_on_a_schedule_as_well_as_on_a_push():
     # for every request left waiting. The two belong together.
     assert "gh pr list --state open" in src, \
         "a scheduled reminder MUST skip what it has already asked about"
+
+
+def test_a_redeposited_note_records_what_changed():
+    """A note past its first deposit carries a `## History` section.
+
+    Never changing a published note silently is the one thing every correction
+    policy agrees on, and the machinery cannot enforce the prose -- but it can
+    notice that a note has been deposited more than once and says nothing
+    about it. `archived_version` is the deposited version, so a `version`
+    ahead of `1.0.0` that has been deposited is a note that has moved.
+    """
+    import re as _re
+    missing = []
+    for meta_path in sorted((ROOT / "articles").glob("*/metadata.yml")):
+        text = meta_path.read_text(encoding="utf-8")
+
+        def field(key):
+            m = _re.search(r"^%s:\s*(.+?)\s*$" % key, text, _re.M)
+            if not m:
+                return None
+            v = m.group(1).strip().strip('"').strip("'")
+            return None if v in ("null", "~", "") else v
+
+        archived = field("archived_version")
+        # deposited, and at a version past the first
+        if not archived or archived == "1.0.0":
+            continue
+        slug = meta_path.parent.name
+        article = meta_path.parent / ("%s.md" % slug)
+        if not article.exists():
+            continue
+        body = article.read_text(encoding="utf-8")
+        if not _re.search(r"^##+\s+History\s*$", body, _re.M):
+            missing.append("%s (deposited at %s)" % (slug, archived))
+    assert not missing, (
+        "these notes were deposited past 1.0.0 and carry no History section, "
+        "so a reader cannot tell what changed: %s" % ", ".join(missing))