Update doc/development/documentation/styleguide/index.md

doc/development/documentation/styleguide/index.md

@@ -1757,7 +1757,7 @@ badges and tooltips (`<span class="badge-trigger free">`).
 | _Only_ GitLab Ultimate SaaS (no self-managed instances)                   | `**(ULTIMATE SAAS)**` |
 
 Topics that mention the `gitlab.rb` file are referring to
-self-managed instances of GitLab. To prevent confusion, include the relevant `TIER ONLY`
+self-managed instances of GitLab. To prevent confusion, include the relevant `TIER SELF`
 tier badge on the highest applicable heading level on
 the page.