Sizzle is a feather type, not a distinct breed. I'm not sure what sort of development has been done with them, but I've always been told breeding two sizzles together was a bad thing to do, and two sizzle genes made a very ugly bird with possible other issues. So I don't know how that could be developed into healthy true to type birds with strong feathers.
I've never kept or bred sizzles so all I have is hear say. I might be totally wrong about breeding them, but I know I'm not wrong on calling it a feather type.
Again thank you. It seems obvious that these terms are vague and hold different meaning depending on the person.
Hens go broody when you don’t want them to… and won’t go broody when you do. 
