diff --git a/README.md b/README.md
index aae821c..f6340e2 100644
--- a/README.md
+++ b/README.md
@@ -59,4 +59,6 @@ config/chat_list.txt
 
 You might want to run the command once without filtering, then paste the chat
 name column from the spreadsheet into config/chat_list.txt and narrow down to
-only the ones you care about and run it again with -f.
+only the ones you care about and run it again with -f. This will ensure the
+output spreadsheet only has columns for users in the groups you care about, and
+not every single user you ever saw on Signal.