1. If your app may be used by children (even if not the primary audience), proactively declare it as a Families App; 2. Only use ad SDKs certified by the Google Play Families Self-Certified Ads SDK Program; 3. Never collect children's personal information (including AAID, device data, etc.); 4. Parent gates must not be easily bypassable; 5. Social/chat features require parent control mechanisms.