Are you sure your incarcerated friend is qualified to implement an rx4? Restrictions are as follows:
Those entered to prevent an unlawful or invalid disposition by a proprietor whose powers are limited by statute or under the general law
Those entered as a result of an application by someone who was obliged to apply under rule 94 of the Land Registration Rules 2003
Any that the registrar is obliged to enter
Those entered to reflect a limitation in an order of the court or the registrar or a limitation in an undertaking given in place of an order
Any that the court has ordered the registrar to enter