Merge pull request #262767 from nolavime/patch-153

Update alerts-processing-rules.md

Author: prmerger-automator[bot]

articles/azure-monitor/alerts/alerts-processing-rules.md

@@ -76,7 +76,8 @@ Severity |  The rule applies only to alerts with the selected severities. |
 * If you define multiple filters in a rule, all the rules apply. There's a logical AND between all filters.  
   For example, if you set both `resource type = "Virtual Machines"` and `severity = "Sev0"`, then the rule applies only for `Sev0` alerts on virtual machines in the scope.
 * Each filter can include up to five values. There's a logical OR between the values.  
-  For example, if you set `description contains "this, that" (in the field there is no need to write the apostrophes), then the rule applies only to alerts whose description contains either `this` or `that`. 
+  For example, if you set `description contains "this, that" (in the field there is no need to write the apostrophes), then the rule applies only to alerts whose description contains either `this` or `that`.
+* Notice that you dont have any spaces (before, after or between) the string that is matched it will effect the matching of the filter.
 
 ### What should this rule do?