By contrast, contractual rights are rights enforceable against particular persons. Property rights may, however, arise from a contract; the two systems of rights overlap. In relation to the sale of land, for example, two sets of legal relationships exist alongside one another: the contractual right to sue for damages, and the property right exercisable over the land. More minor property rights may be created by contract, as in the case of easements, covenants, and equitable servitudes.