I have an 'Affordable Rent' tenancy with a famous London HA that seem anything but charitable to me.
Apparently all their new tenancies will be offered as these.
I was offered it as part of the normal council housing bidding system. They invited the top 5 people to view it and I was 5th place.
The man doing the viewing said that he wished I could have it over the other 4 (who all wanted it) as I wasn't on benefits and I was the sort of tenant that the HA wanted.
A week later he rang me to give me the news that he had been told to offer me the flat. He even asked if I knew somebody in the HA as I was not supposed to be next on the list! 
I think certain HAs are trying to price out certain types of tenants - the tenants they were set up to help in the first place. 
* Yes I know it's rather hypocritical of me to complain about something that has benefitted me- but, well, I'm not exactly rich myself- just earn a bit too much to claim HB. And my rent isn't exactly 'affordable' either (40% if my monthly wage).