diff --git a/__tests__/spelling-ignore.yml b/__tests__/spelling-ignore.yml
index f3078a8b64..36aa1235bc 100644
--- a/__tests__/spelling-ignore.yml
+++ b/__tests__/spelling-ignore.yml
@@ -14,6 +14,7 @@
# Tag(s)
- svg # `aria-query` dom tags does not list `svg`
- xhtml
+- XHTML
- DOCTYPE
- iFrame # used to demonstrate bad spelling
- Iframe
diff --git a/_rules/consistent-navigation-oe3rrh.md b/_rules/consistent-navigation-oe3rrh.md
new file mode 100644
index 0000000000..9b20ab1a48
--- /dev/null
+++ b/_rules/consistent-navigation-oe3rrh.md
@@ -0,0 +1,143 @@
+---
+id: oe3rrh
+name: Consistent navigation
+rule_type: atomic
+description: |
+ This rule checks whether Navigational mechanisms that are repeated on multiple Web pages within a set of Web pages occur in the same relative order each time they are repeated, unless a change is initiated by the user.
+
+accessibility_requirements:
+ wcag2.1:3.2.3: # Consistent Navigation (AA)
+ forConformance: true
+ failed: not satisfied
+ passed: further testing needed
+ inapplicable: further testing needed
+input_aspects:
+ - CSS Styling
+ - DOM tree
+acknowledgments:
+ authors:
+ - Chris Loiselle
+ - Helen Burge
+---
+
+## Applicability
+
+This rule applies to any two pages within a given [set of pages][].
+
+## Expectation
+
+For each target, [navigational mechanisms][] that are present on both pages appear in the same relative order.
+
+## Background
+
+### Assumptions
+
+"Same relative order" means that secondary navigation items may change the original location of the elements. They can be present without affecting the outcome of this test.
+
+### Accessibility Support
+
+There are no accessibility support issues known.
+
+### Bibliography
+
+- [Understanding Success Criterion 3.2.3: Consistent Navigation](https://www.w3.org/WAI/WCAG22/Understanding/consistent-navigation.html)
+
+## Test Cases
+
+Procedure
+Check to see if a navigation mechanism is being used on more than one Web page.
+Check the default presentation of the navigation mechanism on each page to see if the list of links are in the same relative order on each Web page.
+"Same relative order" means that secondary navigation items may be in between the link items on some pages. They can be present without affecting the outcome of this test.
+
+Expected Results
+If #1 is true and #2 is false, then this failure condition applies and content fails the Success Criterion.
+
+### Passed
+
+
+A search field is the last item on every Web page in a site. Users can quickly locate the search function.
+
+An expanding navigation menu
+
+A navigation menu includes a list of seven items with links to the main sections of a site. When a user selects one of these items, a list of sub-navigation items is inserted into the top-level navigation menu.
+
+Consistently positioned skip navigation controls
+
+A "skip navigation" (or "skip to main content") link is included as the first link on every page in a Web site. The link allows users to quickly bypass heading information and navigational content and begin interacting with the main content of a page.
+
+Skip to navigation link
+
+Navigational content is consistently located at the end of each page in a set of Web pages. A "skip to navigation" link is consistently located at the beginning of each page so that keyboard users can easily locate it when needed.
+
+#### Passed Example 1
+
+A consistently located control. Presenting repeated components in the same relative order each time they appear.
+
+
+Examples of a navigation mechanism that presents links in same order.
+
+Page 1 Menu
+
+
+Page 2 Menu
+
+
+
+#### Passed Example 2
+
+...
+
+### Failed
+
+#### Failed Example 1
+
+##### Description
+
+This describes a failure condition for all techniques involving navigation mechanisms that are repeated on multiple Web pages within a set of Web pages (Success Criterion 3.2.3). If the mechanism presents the order of links in a different order on two or more pages, then the failure is triggered.
+
+Example 1: An XHTML menu presenting a series of links that are in a different relative order on two different pages
+Examples of a navigation mechanism that presents links in a different order.
+
+Page 1 Menu
+
+
+Page 2 Menu
+
+
+
+```html
+
+```
+
+### Inapplicable
+
+#### Inapplicable Example 1
+
+Description...
+
+```html
+
+```
+
+[set of pages]: #set-of-pages 'Definition of set of pages'
+[navigational mechanisms]: #navigational-mechanisms 'Definition of a navigational mechanism'
diff --git a/package.json b/package.json
index e4f6daa691..8239e20fce 100644
--- a/package.json
+++ b/package.json
@@ -123,6 +123,10 @@
{
"name": "Wilco Fiers",
"url": "https://github.com/wilcofiers"
+ },
+ {
+ "name": "Chris Loiselle",
+ "url": "https://github.com/ChrisLoiselle"
}
],
"devDependencies": {
diff --git a/pages/glossary/navigational-mechanisms.md b/pages/glossary/navigational-mechanisms.md
new file mode 100644
index 0000000000..22a7c977d1
--- /dev/null
+++ b/pages/glossary/navigational-mechanisms.md
@@ -0,0 +1,8 @@
+---
+title: Navigational Mechanisms
+key: navigational-mechanisms
+unambiguous: true
+objective: true
+---
+
+A method for how a user can move through a series of documents, or [navigation across documments](https://html.spec.whatwg.org/#navigating-across-documents).
diff --git a/pages/glossary/set-of-pages.md b/pages/glossary/set-of-pages.md
new file mode 100644
index 0000000000..c090bb2cf9
--- /dev/null
+++ b/pages/glossary/set-of-pages.md
@@ -0,0 +1,10 @@
+---
+title: Set of pages
+key: set-of-pages
+unambiguous: true
+objective: false
+---
+
+A _set of pages_ is a set of [web pages][] that are in a defined group or brand (also known as [top-level browsing context](https://html.spec.whatwg.org/#top-level-browsing-context)) to require consistent [elements in the DOM](https://html.spec.whatwg.org/#elements-in-the-dom).
+
+[web pages]: #web-page-html 'Definition of web page'