diff --git a/README.md b/README.md
index 4f84ff804..38c2ecc76 100644
--- a/README.md
+++ b/README.md
@@ -150,6 +150,8 @@ cd scripts
 
 This script retrieves the bibliography from Zotero, formats it appropriately, and places the individual JSON files in `static/data/bibItems/`.
 
+Entries marked as deleted in Zotero are recorded in `data/bibliography/removed.json`. The custom 404 page uses that list to recognize former bibliography URLs and show the removed entry's title. The file is merged, not replaced, so entries that Zotero has already purged are retained.
+
 ---
 
 ## Local Development
@@ -323,8 +325,8 @@ repository's GitHub Pages site:
 
 | Deployment | URL |
 |------------|-----|
-| Staging root | `https://interlisp.github.io/Interlisp.staging/` |
-| PR #123 preview | `https://interlisp.github.io/Interlisp.staging/pr-123/` |
+| Staging root | `https://interlisp.org/Interlisp.staging/` |
+| PR #123 preview | `https://interlisp.org/Interlisp.staging/pr-123/` |
 
 When a PR is opened or updated, the production workflow (`gh-pages.yml`)
 triggers the `deploy-preview` workflow in the staging repository, which:
@@ -358,6 +360,7 @@ The repository follows the standard [Hugo directory structure](https://gohugo.io
 | `assets/` | Custom global resources (CSS, JS, icons, SCSS) |
 | `config/` | Site configuration for different environments |
 | `content/en/` | All website content (English only) |
+| `data/` | Build-time data files |
 | `layouts/` | Hugo layout templates and overrides |
 | `static/` | Files copied directly to the built site |
 
@@ -395,6 +398,13 @@ The repository follows the standard [Hugo directory structure](https://gohugo.io
 
 </details>
 
+<details>
+<summary><strong>data/</strong> — Build-time data</summary>
+
+- `bibliography/removed.json` — Keys and titles of bibliography entries removed from Zotero (read by the 404 page)
+
+</details>
+
 <details>
 <summary><strong>static/</strong> — Static files</summary>
 
@@ -468,3 +478,4 @@ Modifying search scope requires updating the Google Custom Search engine setting
 This project is licensed under the MIT License — see the [LICENSE](LICENSE) file for details.
 
 Copyright (c) 2026 Interlisp.org
+
diff --git a/config/staging/hugo.yaml b/config/staging/hugo.yaml
index 09e8b8ee2..2b6526125 100644
--- a/config/staging/hugo.yaml
+++ b/config/staging/hugo.yaml
@@ -1,4 +1,7 @@
-baseURL: https://interlisp.github.io/Interlisp.staging/
+baseURL: https://interlisp.org/Interlisp.staging/
+
+# Per-PR previews override this at build time so that links stay inside the
+# preview, e.g. https://interlisp.org/Interlisp.staging/pr-<N>/
 
 locale: en-us
 
diff --git a/content/en/history/_index.md b/content/en/history/_index.md
index a4dd04593..71626f8c9 100644
--- a/content/en/history/_index.md
+++ b/content/en/history/_index.md
@@ -4,6 +4,7 @@ weight: 500
 type: docs
 aliases:
  - /medley/history/
+ - /doc/info/history.html
 ---
 
 ## The Short History
diff --git a/content/en/project/partners/_index.md b/content/en/project/partners/_index.md
index bb8e505e7..a753bbcc7 100644
--- a/content/en/project/partners/_index.md
+++ b/content/en/project/partners/_index.md
@@ -4,6 +4,7 @@ weight: 18
 type: docs
 aliases:
  - /medley/project/partners
+ - /about/partners/
 ---
 
 ### [Software Preservation Network](https://www.softwarepreservationnetwork.org/about/)
diff --git a/content/en/software/install-and-run/_index.md b/content/en/software/install-and-run/_index.md
index f9a6df6ab..fe5449567 100644
--- a/content/en/software/install-and-run/_index.md
+++ b/content/en/software/install-and-run/_index.md
@@ -7,6 +7,7 @@ aliases:
  - /developing/
  - /software/emu-compat/
  - /using/running/
+ - /running/running-with-docker
 weight: 10
 type: docs
 ---
diff --git a/content/en/software/install-and-run/windows/_index.md b/content/en/software/install-and-run/windows/_index.md
index fd29c1632..dcde3bfb8 100644
--- a/content/en/software/install-and-run/windows/_index.md
+++ b/content/en/software/install-and-run/windows/_index.md
@@ -3,6 +3,8 @@ title: Install and Run on Windows
 linkTitle: Windows
 weight: 40
 type: docs
+aliases:
+ - /medley/using/running/runnning-on-win
 ---
 
 There are two ways to install and run Medley on Windows. These two ways result in (nearly) identical Medley experiences, but differ in how Medley is installed and started.
diff --git a/content/en/software/using-medley/online-using.md b/content/en/software/using-medley/online-using.md
index 5e2f341b7..4ab6a88ea 100644
--- a/content/en/software/using-medley/online-using.md
+++ b/content/en/software/using-medley/online-using.md
@@ -2,6 +2,8 @@
 title: Using Medley Online
 weight: 40
 type: docs
+aliases:
+ - /running/online/usingonline
 ---
 
 
diff --git a/data/bibliography/removed.json b/data/bibliography/removed.json
new file mode 100644
index 000000000..629d58868
--- /dev/null
+++ b/data/bibliography/removed.json
@@ -0,0 +1,66 @@
+[
+  {
+    "key": "47P4BUHS",
+    "title": "Script for testing defstruct and the inspector with defstruct"
+  },
+  {
+    "key": "4R2EXMY4",
+    "title": "TEST APPRENTICE"
+  },
+  {
+    "key": "59UEUE22",
+    "title": "THE INTERLISP-D TESTING SYSTEM - USER GUIDE"
+  },
+  {
+    "key": "7KUMIRNC",
+    "title": "Special Files on <Test>ARs>"
+  },
+  {
+    "key": "D8B2SFFU",
+    "title": "Running AR Test Cases & Recording the Results"
+  },
+  {
+    "key": "ERU4YWDT",
+    "title": "Script for INSPECTALLFIELDSFLG"
+  },
+  {
+    "key": "F7XLXRG5",
+    "title": "Lyric Manual Test procedures"
+  },
+  {
+    "key": "JFGREFUI",
+    "title": "THE INTERLISP-D TESTING SYSTEM"
+  },
+  {
+    "key": "KHWFGC5M",
+    "title": "Debugger, Error System, and Unwinder test report"
+  },
+  {
+    "key": "LJQYU5HX",
+    "title": "Scripts for testing the record package"
+  },
+  {
+    "key": "RJLLRQDR",
+    "title": "SEdit test report"
+  },
+  {
+    "key": "SHRDJ9J4",
+    "title": "Testing Report"
+  },
+  {
+    "key": "SVIQ724G",
+    "title": "Test Utilities"
+  },
+  {
+    "key": "TAYYCYB8",
+    "title": "DEdit test report"
+  },
+  {
+    "key": "TTHB6JCX",
+    "title": "Testing the programmatic interface to INSPECTW"
+  },
+  {
+    "key": "UIS8C4AI",
+    "title": "Script to check code inspectors on frames"
+  }
+]
diff --git a/layouts/404.html b/layouts/404.html
index 2471a8337..4c9705cfa 100644
--- a/layouts/404.html
+++ b/layouts/404.html
@@ -5,11 +5,36 @@
   </aside>
   <main class="col-12 col-md-9 col-xl-8 ps-md-5 pt-0" role="main">
     <div class="td-content mt-0 pt-0">
-      <h1 class="mt-0">Page Not Found</h1>
-      <header class="article-meta"></header>
-      <p>The page you were looking for does not exist. It may have been moved or removed.</p>
-      <p>You can use the search box or browse the site sections on the left to find what you are looking for.</p>
-      <p>Or <a href="{{ "" | relURL }}">return to the homepage</a>.</p>
+      <div id="not-found-generic">
+        <h1 class="mt-0">Page Not Found</h1>
+        <header class="article-meta"></header>
+        <p>The page you were looking for does not exist. It may have been moved or removed.</p>
+        <p>You can use the search box or browse the site sections on the left to find what you are looking for.</p>
+        <p>Or <a href="{{ "" | relURL }}">return to the homepage</a>.</p>
+      </div>
+
+      <div id="not-found-bibliography" class="d-none">
+        <h1 class="mt-0">Bibliography Entry Not Found</h1>
+        <header class="article-meta"></header>
+        <p>
+          The bibliography entry <code id="not-found-bib-key"></code><span id="not-found-bib-title-wrap"> &mdash; <cite id="not-found-bib-title"></cite></span>
+          is no longer available.
+        </p>
+        <p>
+          The Interlisp bibliography is generated from our
+          <a href="https://www.zotero.org/groups/2914042/interlisp">Zotero group library</a>.
+          Entries may be removed or reclassified when the library changes, which removes
+          the corresponding page from this site. If you followed a link from another
+          site, that link may be out of date.
+        </p>
+        <p>You can:</p>
+        <ul>
+          <li><a id="not-found-bib-browse" href="{{ "history/bibliography/" | relURL }}">Browse the bibliography</a></li>
+          <li><a id="not-found-bib-zotero" href="https://www.zotero.org/groups/2914042/interlisp" rel="noopener">View the item in Zotero</a> (the record may still be available)</li>
+          <li><a id="not-found-bib-intake" href="{{ "history/bibliography/intake/" | relURL }}">Report a missing or incorrect entry</a></li>
+        </ul>
+        <p>Or <a id="not-found-bib-home" href="{{ "" | relURL }}">return to the homepage</a>.</p>
+      </div>
     </div>
   </main>
   <aside class="d-none d-xl-block col-xl-2 td-sidebar-toc d-print-none pt-0 mt-0">
@@ -19,4 +44,89 @@ <h1 class="mt-0">Page Not Found</h1>
     </div>
   </aside>
 </div>
+
+{{- $bibData := index hugo.Data "bibliography" -}}
+{{- $removed := slice -}}
+{{- with $bibData -}}
+  {{- $removed = .removed | default (slice) -}}
+{{- end -}}
+<script type="application/json" id="bibliography-removed-data">{{ $removed | jsonify | safeJS }}</script>
+<script id="not-found-script">
+  (function () {
+    const path = window.location.pathname;
+    console.log("[404 Script] Pathname:", path);
+
+    // Match the end of the path so this also works when the 404 page is
+    // served for a staging preview, e.g.
+    // /Interlisp.staging/pr-355/history/bibliography/<key>/.
+    // GitHub Pages supports only one custom 404 per site, and a preview can be
+    // served by the domain-level 404 page, so the build-time baseURL cannot be
+    // used to decide what kind of URL this is.
+    const match = path.match(/\/history\/bibliography\/([A-Za-z0-9]{8})\/?$/);
+    console.log("[404 Script] Regex match result:", match);
+    if (!match) {
+      console.log("[404 Script] No bibliography entry match - showing generic 404");
+      return;
+    }
+
+    const key = match[1];
+    // Everything before "history/", including any staging/PR prefix.
+    const siteRoot = path.slice(0, match.index + 1);
+
+    console.log("[404 Script] Found bibliography entry - key:", key, "siteRoot:", siteRoot);
+
+    const generic = document.getElementById("not-found-generic");
+    const bib = document.getElementById("not-found-bibliography");
+    console.log("[404 Script] Found elements - generic:", !!generic, "bib:", !!bib);
+    if (!generic || !bib) {
+      console.log("[404 Script] ERROR: Missing DOM elements");
+      return;
+    }
+
+    generic.classList.add("d-none");
+    bib.classList.remove("d-none");
+    console.log("[404 Script] Toggled visibility - generic hidden, bib shown");
+
+    // Keep the links inside the same preview when the page is served from a
+    // staging path.
+    document.getElementById("not-found-bib-browse").href =
+      siteRoot + "history/bibliography/";
+    document.getElementById("not-found-bib-intake").href =
+      siteRoot + "history/bibliography/intake/";
+    document.getElementById("not-found-bib-home").href = siteRoot;
+
+    const displayKey = key.toUpperCase();
+    document.getElementById("not-found-bib-key").textContent = displayKey;
+    document.title = "Bibliography entry not found | The Medley Interlisp Project";
+    console.log("[404 Script] Set key and title - key display:", displayKey);
+
+    let removed = [];
+    const data = document.getElementById("bibliography-removed-data");
+    console.log("[404 Script] Found removed data element:", !!data);
+    if (data) {
+      try {
+        removed = JSON.parse(data.textContent) || [];
+        console.log("[404 Script] Loaded removed entries count:", removed.length);
+      } catch (e) {
+        console.error("[404 Script] Failed to parse removed data:", e);
+        removed = [];
+      }
+    }
+
+    const entry = removed.find(function (item) {
+      return String(item.key || "").toUpperCase() === displayKey;
+    });
+    if (entry && entry.title) {
+      console.log("[404 Script] Found entry in removed list:", entry.title);
+      document.getElementById("not-found-bib-title").textContent = entry.title;
+    } else {
+      console.log("[404 Script] Entry not in removed list - hiding title wrap");
+      document.getElementById("not-found-bib-title-wrap").classList.add("d-none");
+    }
+
+    document.getElementById("not-found-bib-zotero").href =
+      "https://www.zotero.org/groups/2914042/items/" + encodeURIComponent(displayKey);
+    console.log("[404 Script] Completed successfully");
+  })();
+</script>
 {{ end }}
diff --git a/layouts/_partials/hooks/head-end.html b/layouts/_partials/hooks/head-end.html
index 14f526e3c..25c9439ff 100644
--- a/layouts/_partials/hooks/head-end.html
+++ b/layouts/_partials/hooks/head-end.html
@@ -8,4 +8,9 @@
 {{ with .Params.robots }}
 <meta name="robots" content="{{ . | htmlEscape }}">
 {{ end }}
+{{- /* The 404 page is served with an HTTP 404 status.  Tell crawlers not to
+       index it even if they ignore the status code. */ -}}
+{{ if eq .Kind "404" }}
+<meta name="robots" content="noindex, follow">
+{{ end }}
 {{ partial "bibliography-json-ld.html" . }}
diff --git a/scripts/update_bibliography.sh b/scripts/update_bibliography.sh
index ab9dae234..2e27a3671 100755
--- a/scripts/update_bibliography.sh
+++ b/scripts/update_bibliography.sh
@@ -355,6 +355,24 @@ if $debugFiles ; then
 fi
 
 showInfo 5 "Delete items that Zotero indicated as such."
+# Save the deleted entries before filtering them out.  The custom 404 page uses
+# this list to identify bibliography URLs that were removed and show their
+# titles.  Keep only keys and titles; the list is embedded in 404.html at build
+# time.  Merge with the existing file instead of replacing it: once Zotero
+# purges an item, the API no longer reports it as deleted, but its old URL can
+# still be requested by search engines and external links.
+REMOVED_DATA_FILE="./../data/bibliography/removed.json"
+mkdir -p "$(dirname "$REMOVED_DATA_FILE")"
+deletedItems=$(jq 'map(select(.deleted)) | map({key: .key, title: (.title // "")})' <<< "$items")
+if [[ -f "$REMOVED_DATA_FILE" ]]; then
+  # Newly deleted entries override older records with the same key.
+  jq --argjson deleted "$deletedItems" \
+    '(INDEX(.key) + ($deleted | INDEX(.key))) | [.[]] | sort_by(.key)' \
+    "$REMOVED_DATA_FILE" > "$REMOVED_DATA_FILE.tmp"
+else
+  printf '%s\n' "$deletedItems" > "$REMOVED_DATA_FILE.tmp"
+fi
+mv "$REMOVED_DATA_FILE.tmp" "$REMOVED_DATA_FILE"
 beforeCount=$(jq '. | length' <<< "$items")
 items=$(jq 'map(select(.deleted|not))' <<< "$items")
 afterCount=$(jq '. | length' <<< "$items")
diff --git a/staging-site-design.md b/staging-site-design.md
index 91abf999f..365cd11d7 100644
--- a/staging-site-design.md
+++ b/staging-site-design.md
@@ -107,7 +107,7 @@ In the staging repo, `deploy-preview.yml`:
 
 1. The `build` job calls the same shared reusable workflow against the PR head
    commit with `hugo-environment: staging`, the per-PR baseURL
-   (`https://interlisp.github.io/Interlisp.staging/pr-<N>/`), and
+   (`https://interlisp.org/Interlisp.staging/pr-<N>/`), and
    `run-build-tests: false`.
 2. The `deploy` job downloads the `github-pages` artifact, extracts
    `artifact.tar`, and deploys the contents to the `pr-<N>/` subdirectory of
@@ -191,8 +191,8 @@ the staging repo.
 - **Pages:** staging repo serves from the `gh-pages` branch ("Deploy from a
   branch", not "GitHub Actions").
 - **Staging config:** `config/staging/hugo.yaml` sets
-  `baseURL: https://interlisp.github.io/Interlisp.staging/` and titles pages
-  "Staging Environment".
+  `baseURL: https://interlisp.org/Interlisp.staging/` and titles pages
+  "Staging Environment". Per-PR previews override the baseURL at build time.
 - **Repo pins:** both callers pin the shared workflow at `@main` of
   `Interlisp/shared-workflows`.
 - **`Interlisp/shared-workflows` `main`:** protected — all updates land via PR
diff --git a/static/IRM_files/content.htm b/static/IRM_files/content.htm
new file mode 100644
index 000000000..78583a9e9
--- /dev/null
+++ b/static/IRM_files/content.htm
@@ -0,0 +1,3 @@
+<script type="text/javascript">
+	document.location = "/documentation/IRM.pdf"
+</script>
diff --git a/tests/test_hugo_build.py b/tests/test_hugo_build.py
index 55c22fee1..ef44ecac7 100644
--- a/tests/test_hugo_build.py
+++ b/tests/test_hugo_build.py
@@ -20,8 +20,11 @@
     PYTEST_FORCE_HUGO_BUILD=1 pytest tests/test_hugo_build.py -v
 """
 
+import json
 import os
 import re
+import shutil
+import subprocess
 import xml.etree.ElementTree as ET
 from pathlib import Path
 from urllib.parse import urlparse
@@ -53,6 +56,86 @@ def _get_baseurl_path() -> str:
     return ""
 
 
+def _run_404_script(content: str, path: str, tmp_path: Path) -> dict:
+    """Execute the built 404 page script in Node with a minimal fake DOM.
+
+    Returns the visible state and rewritten links for ``path``.
+    """
+    node = shutil.which("node")
+    if not node:
+        pytest.skip("Node.js is required to exercise the 404 page script")
+
+    script_match = re.search(
+        r'<script id="not-found-script">(.*?)</script>', content, re.DOTALL
+    )
+    assert script_match, "not-found-script block not found in 404.html"
+
+    data_match = re.search(
+        r'<script type="application/json" id="bibliography-removed-data">(.*?)</script>',
+        content,
+        re.DOTALL,
+    )
+    assert data_match, "bibliography removed data not found in 404.html"
+
+    harness = "\n".join(
+        [
+            "function makeElement(id) {",
+            "  const classes = new Set();",
+            "  return {",
+            "    id,",
+            '    textContent: "",',
+            '    href: "",',
+            "    classes,",
+            "    classList: {",
+            "      add: (c) => classes.add(c),",
+            "      remove: (c) => classes.delete(c),",
+            "      contains: (c) => classes.has(c),",
+            "    },",
+            "  };",
+            "}",
+            "const ids = [",
+            '  "not-found-generic", "not-found-bibliography",',
+            '  "not-found-bib-key", "not-found-bib-title",',
+            '  "not-found-bib-title-wrap", "not-found-bib-zotero",',
+            '  "not-found-bib-browse", "not-found-bib-intake",',
+            '  "not-found-bib-home",',
+            "];",
+            "const elements = Object.fromEntries(ids.map((id) => [id, makeElement(id)]));",
+            'elements["not-found-bibliography"].classList.add("d-none");',
+            'elements["not-found-bib-title-wrap"].classList.add("d-none");',
+            "const removedData = { textContent: "
+            + json.dumps(data_match.group(1))
+            + " };",
+            "const byId = Object.assign({}, elements, {",
+            '  "bibliography-removed-data": removedData,',
+            "});",
+            "const window = { location: { pathname: "
+            + json.dumps(path)
+            + " } };",
+            'const document = { title: "", getElementById: (id) => byId[id] || null };',
+            script_match.group(1),
+            "console.log(JSON.stringify({",
+            '  visible: !elements["not-found-bibliography"].classes.has("d-none"),',
+            '  key: elements["not-found-bib-key"].textContent,',
+            '  browse: elements["not-found-bib-browse"].href,',
+            '  intake: elements["not-found-bib-intake"].href,',
+            '  home: elements["not-found-bib-home"].href,',
+            '  title: document.title,',
+            "}));",
+        ]
+    )
+
+    script_file = tmp_path / "check-404.js"
+    script_file.write_text(harness, encoding="utf-8")
+    result = subprocess.run(
+        [node, str(script_file)],
+        capture_output=True,
+        text=True,
+        check=True,
+    )
+    return json.loads(result.stdout.strip().splitlines()[-1])
+
+
 # ---------------------------------------------------------------------------
 # Build process tests
 # ---------------------------------------------------------------------------
@@ -119,6 +202,116 @@ def test_page_exists(self, path: str) -> None:
         )
 
 
+class TestNotFoundPage:
+    """The custom 404 page must handle removed bibliography entries."""
+
+    @pytest.fixture(autouse=True)
+    def page(self):
+        path = PROD_PUBLIC / "404.html"
+        if not path.exists():
+            pytest.skip("404.html not found — run a production build first")
+        self.content = path.read_text(encoding="utf-8", errors="ignore")
+
+    def test_has_bibliography_fallback(self) -> None:
+        assert 'id="not-found-bibliography"' in self.content
+        assert "/history/bibliography/" in self.content
+        assert "bibliography-removed-data" in self.content
+
+    def test_embeds_removed_entries_as_json(self) -> None:
+        match = re.search(
+            r'<script type="application/json" id="bibliography-removed-data">(.*?)</script>',
+            self.content,
+            re.DOTALL,
+        )
+        assert match, "Removed-bibliography data block not found in 404.html"
+        removed = json.loads(match.group(1))
+        assert isinstance(removed, list)
+        for entry in removed:
+            assert isinstance(entry.get("key"), str) and entry["key"]
+            assert isinstance(entry.get("title"), str)
+
+    def test_is_noindex(self) -> None:
+        assert re.search(
+            r'<meta name="robots" content="[^"]*noindex',
+            self.content,
+        ), "404 page must be marked noindex"
+
+    def test_bibliography_match_ignores_site_prefix(self) -> None:
+        """Staging previews live under /Interlisp.staging/pr-<N>/ and are
+        served by the domain-level 404 page, so detection must match the end
+        of the path rather than a build-time baseURL prefix."""
+        assert r"/\/history\/bibliography\/([A-Za-z0-9]{8})\/?$/" in self.content
+        assert "startsWith(bibRoot)" not in self.content
+        for element_id in (
+            "not-found-bib-browse",
+            "not-found-bib-intake",
+            "not-found-bib-home",
+        ):
+            assert f'id="{element_id}"' in self.content
+
+    @pytest.mark.parametrize(
+        ("path", "expected_root"),
+        (
+            ("/history/bibliography/wxmqhqnz/", "/"),
+            ("/history/bibliography/WXMQHQNZ", "/"),
+            (
+                "/Interlisp.staging/pr-355/history/bibliography/wxmqhqnz/",
+                "/Interlisp.staging/pr-355/",
+            ),
+        ),
+    )
+    def test_bibliography_links_follow_site_prefix(
+        self, path: str, expected_root: str, tmp_path: Path
+    ) -> None:
+        result = _run_404_script(self.content, path, tmp_path)
+        assert result["visible"] is True
+        assert result["key"] == "WXMQHQNZ"
+        assert result["browse"] == expected_root + "history/bibliography/"
+        assert result["intake"] == expected_root + "history/bibliography/intake/"
+        assert result["home"] == expected_root
+
+    @pytest.mark.parametrize(
+        "path",
+        (
+            "/history/bibliography/",
+            "/some/other/page/",
+            "/Interlisp.staging/pr-355/history/bibliography/",
+        ),
+    )
+    def test_non_entry_paths_stay_generic(self, path: str, tmp_path: Path) -> None:
+        result = _run_404_script(self.content, path, tmp_path)
+        assert result["visible"] is False
+
+
+class TestLegacyRedirects:
+    """Aliases and static redirects must exist for known legacy URLs."""
+
+    REDIRECTS = (
+        ("doc/info/history.html", "/history/"),
+        ("about/partners/index.html", "/project/partners/"),
+        ("running/running-with-docker/index.html", "/software/install-and-run/"),
+        (
+            "running/online/usingonline/index.html",
+            "/software/using-medley/online-using/",
+        ),
+        (
+            "medley/using/running/runnning-on-win/index.html",
+            "/software/install-and-run/windows/",
+        ),
+        ("IRM_files/content.htm", "/documentation/IRM.pdf"),
+    )
+
+    @pytest.mark.parametrize(("path", "target"), REDIRECTS)
+    def test_redirect_exists(self, path: str, target: str) -> None:
+        redirect = PROD_PUBLIC / path
+        if not redirect.exists():
+            pytest.skip("public/ not built — run hugo first")
+        content = redirect.read_text(encoding="utf-8", errors="ignore")
+        assert target in content, (
+            f"Redirect {path} does not point at {target}:\n{content[:200]}"
+        )
+
+
 class TestSitemapIntegrity:
     """The sitemap must be valid XML and reference only absolute URLs."""