diff --git a/source/reference/limits.txt b/source/reference/limits.txt
index a637231cbd2..4085495c292 100644
--- a/source/reference/limits.txt
+++ b/source/reference/limits.txt
@@ -516,6 +516,8 @@ Naming Restrictions
 
    - begin with the ``system.`` prefix. (Reserved for internal use.)
 
+   - be the name of a method on db, e.g. "hello".
+
    If your collection name includes special characters, such as the
    underscore character, or begins with numbers, then to access the
    collection use the :method:`db.getCollection()` method in