There are various guides available which provide information on how to make your views known on a planning, listed building or enforcement appeal.
The guides do not apply to any appeal in connection with a householder application, an application for express consent to display an advertisement which has been refused or an application for minor commercial (shop front) development which has been refused, which is proceeding by the written representation's procedure.
Further guidance is available from the Planning Inspectorate. Useful documents include Planning appeals - procedural guide