service/prometheus.md

@@ -734,7 +734,9 @@ See the [PromQL primer][] for more information about queries and the
 
 The `for` field means the alert is not immediately passed down to the
 Alertmanager until that time has passed. It is useful to avoid
-flapping and temporary conditions. Rule of thumbs:
+flapping and temporary conditions. 
+
+Here are some typical `for` delays we use, as a rule of thumb:
 
 - `0s`: checks that already have a built-in time threshold in its
   expression (see below), or critical condition requiring immediate