Child protection groups have welcomed the decision to disclose the contents of a secret manual governing the use of physical restraint in child prisons.
The Youth Justice Board (YJB) has agreed to hand over the instructors' manual detailing techniques used in secure training centres.
The document includes descriptions of "distraction" techniques, which deliberately inflict pain.
Children's Rights Alliance for England (CRAE) officials said the YJB had initially appealed against an order by the Information Commissioner in December 2009 that the document be given to them.
Carolyne Willow, CRAE's national co-ordinator, said: "The YJB and the Ministry of Justice have had six long years to bring everything out into the open.
"Until now, we've seen a compulsive reliance on secrecy and an absolute failure to face up publicly to the disgraceful and unlawful treatment of children the state officially describes as vulnerable."
She called for the Justice Secretary to order an independent judicial inquiry to examine the regimes of these private child prisons going back to 1998.
A Youth Justice Board spokesman said: "The Youth Justice Board has decided to release the Physical Control in Care (PCC) manual, a handbook used by instructors training Secure Training Centre custody officers in safe and appropriate use of restraint techniques.
"The PCC manual is the property of the Ministry of Justice."
A Ministry of Justice spokesman said: "For young people under 18, the use of restraint is a last resort. But where young people's behaviour puts themselves or others at serious risk, staff need to be able to intervene effectively, to protect the safety of all involved."
