The certified copy is signed by a person nominated by the person or agency asking for it. Typically, the person is referred to as an authorised person. The person who is authorised to sign the certificate will vary between countries. Sometimes a person is authorised by legislation to do so (for example a court clerk, solicitor, or notary public), but this is not always so. In some countries, for example the United Kingdom and South Africa, identity documents can also be certified by authorised post office staff.