NO, NO, NO ... Please don't print cards saying I'm carrying a gun and start handing them out to every LEO you see!
However, If you do decide to do that at least make sure you are wearing your official Concealed Carry BADGE pinned prominently to your chest when you hand them the card. :wink:
The need to notify is ALWAYS only when an officer is interacting in an OFFICIAL CAPACITY as stated in the previous posts.
Here in Florida we have no duty to notify and whether you are a permit holder or not IS NOT presented to the officer in the routine radio background check so the decision of if the officer is to know or not is stricktly up to you as a courtesy even during "official interaction".
Of course if they ask ... anytime ... THEN yes, you must disclose that you are carrying regardless of the circumstance of the interaction.