The DPA defines a "data file" as a collection of personal data structured to permit it to be searched by data subjects. Typically, records in alphabetical order will qualify as a data file and electronically stored data also are likely to constitute a data file because the data can be readily searched. The name of the data subject is not the only criterion which results in a collection of personal data constituting a data file if other criteria allow data relating to a single person to be retrieved.