Its an important one.
Wallets, and other forms of identification including name tags can be lost during traumatic accidents.
Most of us who work in the field at Mosquito control still wear our dog tags, and those with allergies etc have added the first response tag to it.
It is difficult to loose that chain hanging around your neck, even when a gator is doing a death roll on you.
If you are unconscious, first responders will check for neck chains, and bracelets for special medical information.
And if the worse happens, at least you are sure your family will be able to obtain closure.