No matter the degree of horizontal or vertical privacy, an easement can still run with the land. Easements are a form of land-ownership interest, while real covenants are promises. Non-possessory property rights, such as rights of way and homeowners association agreements, are common. Over time, two distinct categories of property law were developed to address similar issues in different contexts. The Third Reformulation of the Property Act adopted a unified approach and a new category, called easements, which included all previous classifications.