This is called caves and commons http://c2.com/cgi/wiki?CaveAndCommons http://c2.com/cgi/wiki?CaveAndCommons which is not very common because then the company

This is called caves and commons http://c2.com/cgi/wiki?CaveAndCommons http://c2.com/cgi/wiki?CaveAndCommons which is not very common because then the company has to buy both caves and common space for everyone.