diff --git a/FAQ.md b/FAQ.md
index cb7cc83cc4..fc34223a3a 100644
--- a/FAQ.md
+++ b/FAQ.md
@@ -1153,6 +1153,8 @@ so it is not possible to apply filter rules to the message text.
 Note that large message texts are downloaded on demand on a metered connection to save data.
 
 To debug rules you can long press *Operations* to see logging about the evaluation of rule conditions.
+Since message headers are not downloaded and stored by default to save on battery and data usage and to save storage space
+it is not possible to check which messages would match the rule conditions.
 
 Using filter rules is a pro feature.