diff --git a/µBlock-and-others:-Blocking-ads,-trackers,-malwares.md b/µBlock-and-others:-Blocking-ads,-trackers,-malwares.md
index 034394b..535527e 100644
--- a/µBlock-and-others:-Blocking-ads,-trackers,-malwares.md
+++ b/µBlock-and-others:-Blocking-ads,-trackers,-malwares.md
@@ -73,6 +73,8 @@ I included µBlock with [my own selection of lists](https://github.com/gorhill/u
 
 ### Data diffs
 
+This shows the differences in what was **not** blocked. If something appears on side A but not on side B, this mean side B blocked something not blocked by side A.
+
 - µBlock/Ghostery: https://www.diffchecker.com/7qv6eu3b
 - µBlock/ABP: https://www.diffchecker.com/4c5aox70
 - µBlock/Disconnect: https://www.diffchecker.com/y5gj3ed5