Key:protection title
From OpenStreetMap Wiki
Title or type of protection - not the proper name. An official national predicate or grade, the formal title or type of protection (see level-table). To make differences within one class. At the end it gives a sample of terms.
established as additional key with the boundary=protected_area tag.
values f.e.: wildlife sanctuary, Zapovedniki, Nationalpark, Special Protected Area, World Heritage Convention, Aesthetic Forest, Heritage River, Indian Reserve, ...