An encumbrance is a right to, interest in, or legal liability on real property that does not prohibit passing title to the property but that diminishes its value. Encumbrances can be classified in several ways. They may be financial (ex: liens) or non-financial (ex: easements, private restrictions). Alternatively, they may be divided into those that affect title (ex: lien, legal or equitable charge) or those that affect the use or physical condition of the encumbered property (ex: restrictions, easements, encroachments). Encumbrances include security interests, liens, servitudes (e.g. easements, wayleaves, real covenants, profits a prendre), leases, restrictions, encroachments, and air and subsurface rights. Also, those considered as potentially making the title defeasible are encumbrances, e.g. charging orders, building orders and structure alteration.