Clarify docs coverage of UI text that may run counter to style rules

doc/development/documentation/styleguide.md

@@ -270,8 +270,12 @@ Use sentence case. For example:
 
 #### UI text
 
-When including user interface text, like button labels or menu items, use the same capitalization that's in the UI.
-Standards for this content are listed in the [Pajamas Design System Content section](https://design.gitlab.com/content/punctuation).
+When referring to specific user interface text, like a button label or menu item, use the same capitalization that is displayed in the UI.
+Standards for this content are listed in the [Pajamas Design System Content section](https://design.gitlab.com/content/punctuation) and typically
+match what is called for in this Documentation Style Guide.
+
+If you think there is a mistake in the way the UI text is styled,
+create an issue or an MR to propose a change to the UI text.
 
 #### Feature names