What does a yellow tab on an AED indicate?

A yellow tab on an Automated External Defibrillator (AED) typically indicates that pads are missing. This serves as a visual cue for responders to check the device for the presence of the defibrillation pads since these are critical for delivering an electric shock to a patient in cardiac arrest. It is essential for the AED to have all necessary components ready for immediate response in case of an emergency.

In the context of emergency response, ensuring that an AED is fully equipped with pads is vital, as their absence directly affects the device's readiness for use. Therefore, if the yellow tab is present, it signifies that immediate action may be required to check for the pads before proceeding with use.

If the other options were considered, receiving a signal for a full battery or readiness for use would suggest that the AED is equipped and functional, making these scenarios less likely to be associated with the yellow tab.