An offer is an expression of willingness to contract on specified terms, made with the intention that it is to be binding once accepted by the person to whom it is addressed. There must be an objective manifestation of intent by the offeror to be bound by the offer if accepted by the other party. Therefore, the offeror will be bound if his words or conduct are such as to induce a reasonable third party observer to believe that he intends to be bound, even if in fact he has no such intention. This was held to be the case where a university made an offer of a place to an intending student as a result of a clerical error. An offer can be addressed to a single person, to a specified group of persons, or to the world at large. An example of the latter would be a reward poster for the return of a lost pet.  An offer may be made expressly (by words) or by conduct.