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1. To 'have notice' or be 'on notice' is to have, or be assumed to have, an awareness of some right that may be enforceable against you. The term is widely used in trust law, and those parts ofland and property law where Equity is important. For a discussion of this use of the term, see doctrine of notice.

2. A notice is an entry against aregistered title that seeks to protect a particular person's interest in another person's legal estate. For example, if person A has a right to enforce afreehold covenant against the land owned by person B, then he should enter a notice to that effect on person B's title. Under the land registration act (2002) the terminology used in protecting third-party interests has changed. Where we used to have a notice and a Caution, we now have an Agreed notice and a Unilateral notice. These are used where, respectively, the owner of the estate is, or is not, amenable to the entry being made.