Abstract: A method for the coded tagging of articles, such as garments, comprises fitting to each of a plurality of articles a tagging element, such as a rigid plaque, bearing coded information in the form of portions of the element which permit the passage therethrough of a form of radiation, such as X-rays, which also passes through the material of the articles but to which the rest of the element is opaque. At least the portions of the articles bearing the tagging elements are conveyed in succession between an X-ray emitter and an X-ray detector, the detector producing output signals corresponding to the coded information on each tagging element, the output signals from the detector being supplied to a computer which processes the signals to store and process the coded information on the tagging element.