diff --git a/app/strands_classifier.py b/app/strands_classifier.py
index 0c085c8..4dd5b02 100644
--- a/app/strands_classifier.py
+++ b/app/strands_classifier.py
@@ -14,7 +14,7 @@ ALLOWED_LABELS = {"LINKEDIN", "ADVERTISING", "OTHER"}
 
 SYSTEM_PROMPT = """You classify incoming emails into exactly one label:
 - LINKEDIN: official LinkedIn platform emails (job alerts, invites, network updates, LinkedIn newsletters).
-- ADVERTISING: marketing/promotional/sales emails, newsletters, coupons, deals, brand campaigns.
+- ADVERTISING: marketing/promotional/sales emails, newsletters, coupons, deals, brand campaigns. Do not label as ADVERTISING if the email is purely transactional (e.g. order confirmation, password reset) even if it contains some marketing language. Also do not label as ADVERTISING if the sender is Cybernetica. But if the sender is Cybernetica and the content is clearly promotional (e.g. "Check out our new product"), then label as ADVERTISING. And if the sender is Castorama and the content is about Communauté d'entraide, the label should be ADVERTISING.
 - OTHER: anything else.
 
 Rules: