identification tag placed on a dog's collar; one of two metal identification tags which are worn around a soldier's neck and contain personal information (such as name, serial number and blood type)
metal plate on a dog collar bearing its registration number military identification tag worn on a chain around the neck
Dog tags are metal identification discs that are worn on a chain around the neck by members of the United States armed forces. a small piece of metal that soldiers wear on a chain around their necks with their name, blood type etc written on it