Is the easement subject to any particular formalities?
The notarised format is not a prerequisite for validity; it is also possible to draft it either privately or orally. Nevertheless, in application of Article 28 of the decree of 4 January 1955, constituent acts of easement are subject to land registration. By default, they are unenforceable by successive owners and therefore ineffective.
An agreement on good-neighbourliness which generally creates private rights is not, in theory, subject to land registration.