Where the appellant is detained, the appeal may be made by means of a declaration to the head of the prison.
This declaration shall be recorded, dated and signed by the head of the prison. It shall also be signed by the appellant; if the appellant is unable to sign, this shall be noted by the head of the establishment.
The original or a copy of this document shall be sent without delay to the registry of the court which handed down the contested decision; it shall be transcribed into the register provided for in the third paragraph of Article 502 appended to the document drawn up by the registrar.