What would it do, what would it mean?
As I see it, the Charter might determine and set out common principles between the huge number of stakeholders (governors, practitioners, users, voluntary sector organisations, probation etc.), informing the future development of rehabilitative practices, initiatives and projects.
Like education, the criminal justice field is flooded with ideas, interventions, opinions, politicisation, and public misunderstanding and so the issue isn't really a lack of ideas or opinions. Rather it is, on the one hand, a failure to join up the various stakeholders and developers of innovative practice already in operation and, on the other, the difficulty of mobilising the 'silent majority' among professionals and the public in favour of a more progressive approach.
Ok, I have borrowed this directly from the Education Charter information itself, but the fit is seamless. The RSA Prison Learning Network is working towards something like this; thinking through how we might bring all these critical partners together to share their knowledge, develop their practices, work collaboratively with each other and in partnership with the prison and probation services, encourage greater understanding amongst the public (and media), build and aggregate useful and meaningful evidence and data and incorporate and embed the ‘user voice’ in every stage of design and delivery.