OPSEC (operations security) is a security and risk management process and strategy that classifies information, then determines what is required to protect sensitive information and prevent it from getting into the wrong hands.
For a Prepper this is a vital practice to keep your neighbors from knowing that you are a prepper as they will undoubtedly come knocking when disaster strikes. However, operations security doesn't end with preparation, it also needs to be used during times of survival as well.
When you are one of the few with resources, you need to avoid it becoming public knowledge. Light, smells & waste being produced are telling signs that you are more equipped and will invite trouble.