Apparently it's a license that you can obtain on certain classifications of land (for instance, if it's Crown Land) for the purpose of managing and caring for the land. The area becomes a conservation area and is you're responsibility to care for.
Although the land is not your by title, while you have a license for conservation, it it yours to do with as you please as long as you're acting within the guidelines of the license. Bulldozing the whole place down is not permitted, I would imagine.
Anyway, if you know what I'm talking about, and can help me find the person or department I need to speak to to obtain one, then please get in touch. So far the people my wife and I have spoken to at the Department for Sustainability and the Environment don't seem to know...