Jails in the UK have been told that sex-change inmates must be allowed access to padded bras and make-up to cover stubble growth.
They should also be able to purchase "gender appropriate" clothing from a home shopping catalogue, according to a detailed set of instructions circulated by the Ministry of Justice.
The mandatory guidelines, which come into force next week, state: "An establishment must permit prisoners who consider themselves transsexual and wish to begin gender reassignment to live permanently in their acquired gender."
The 20-page document informs prison officers that "transsexual people, particularly those who have not undergone surgery or extended hormone therapy, may use various items to assist with their presentation in their acquired gender".
"These can range from sophisticated prostheses to padded bras. Regardless of their level of sophistication, access to them can only be restricted in exceptional circumstances," the instructions state.
"These items may only be prohibited when it can be demonstrated that they present a security risk which cannot be reasonably mitigated.
"The test that is applied to these items is the same as that applied to other items in the prison in which the prisoner is held.
"Any restriction of these items could be subject to judicial review. If a prison decides to apply such restrictions, they must be able to provide a detailed and reasonable justification for doing so.
"Both male to female and female to male transsexual people may use make-up to present more convincingly in their acquired gender.
"Make-up that is vital to presenting in the acquired gender, such as foundation to cover up beard growth, may not be restricted."
Unlike male prisoners, sex-change inmates cannot be forced to wear prison uniform if they are punished by being moved to the basic privileges regime.
"Permitting prisoners to live permanently in their acquired gender will include allowing prisoners to dress in clothes appropriate to their acquired gender and adopting gender-appropriate names and modes of address," the guidelines say.
"If prisoners have funds available, they can purchase gender-appropriate clothing from the Argos Additions clothing catalogue."
Visitors can also bring clothing in for them.