I once had a batch of dry-lining boxes with built-in cable clamps, but can't remember where I got them from. I know it's not actually necessary, just was doing a job today where there are two sockets virtually back to back on a stud wall with the T&E just going from one to the other, unsupported. I know I'm being pedantic, but in my view this cable should be secured in some way! Thoughts?!