Hi Polly,
I'm also trying to figure this one out. I was told by the manager of a care home that I went to visit that this could kick in after a continuing care assessment that stressed complex needs.
However I had previously mentioned this to NHS mental health, who laughed (same PCT), and when I asked the social worker yesterday, she didn't know of it.
If it's possible to access it would solve an awful lot of problems for me (my mum and dad have to move care home because of my dad's unpredictable violence, but it looks unlikely that there is a care home in the area that can meet his needs), so am going to be asking about it as much as I can over the next few days.
Sorry not to be more helpful, but I thought it might be useful to share the little I've learned about it so far. Good luck.