Update doc/user/profile/preferences.md

doc/user/profile/preferences.md

@@ -57,7 +57,10 @@ and default views of your dashboard and the projects' landing pages.
 ### Layout width
 
 GitLab can be set up to use different widths depending on your liking. Choose
-between the fixed (max. 1200px) and the fluid (100%) application layout.
+between the fixed (max. `1280px`) and the fluid (`100%`) application layout.
+
+NOTE: **Note:**
+While `1280px` is the standard max width when using fixed layout, some pages still use 100% width, depending on the content.
 
 ### Default dashboard