All—
notices, orders, consents, demands and other documents authorised or required by or under this Act to be given, made or issued by a local authority or the regulator, and
notices and applications authorised or required by or under this Act to be given or made to, or to any officer of, a local authority or the regulator,
shall be in writing.
The appropriate national authority may, by regulations ..., prescribe the form of any notice, advertisement, certificate or other document to be used for any of the purposes of this Act, and if forms are so prescribed those forms or forms to the like effect may be used in all cases to which those forms are applicable.