--- a/testing/eslint-plugin-mozilla/docs/index.rst
+++ b/testing/eslint-plugin-mozilla/docs/index.rst
@@ -8,16 +8,19 @@ Mozilla ESLint Plugin
 ``Cu.import("some/path/Blah.jsm")`` adds Blah to the global scope.
 
 ``import-headjs-globals`` imports globals from head.js and from any files that
 should be imported by head.js (as far as we can correctly resolve the path).
 
 ``mark-test-function-used`` simply marks test (the test method) as used. This
 avoids ESLint telling us that the function is never called.
 
+``var-only-at-top-level`` Marks all var declarations that are not at the top
+level invalid.
+
 +-------+-----------------------+
 | Possible values for all rules |
 +-------+-----------------------+
 | Value | Meaning               |
 +-------+-----------------------+
 | 0     | Deactivated           |
 +-------+-----------------------+
 | 1     | Warning               |