When should/are initials used, in the context of a contract? How are they different from a signature of a full name? Come to think of it, is it required that a person's signature be their first and last name?
To expand on Dale's answer, the general principle applying to acceptance are as follows:
- The offeree's clear and absolute expression of intention and assent must be made in response to, and must exactly match, the terms of the offer.
- This expression must be communicated with the offeror in order to be effective.
This means that a verbal contract is just as binding as a written one, with or without initial or signature. The importance of the initial or signature, as correctly identified by Dale is to be able to hold the offeree to account if a breach of the contract follows.
Importantly, a contract can stipulate in what form the expression of acceptance must take.
In the case of unilateral contracts, such as in adverts (see Carlill v Carbolic Smoke Ball Co. , for a relevant item of UK case law), no expression of acceptance is needed to be received by the offeror - merely attempting to perform the act has been held as adequate acceptance.
For a contract to exist one of the criteria is that the parties agree to be legally bound. There is no requirement for a contract to be signed, initialed or even written down (some exceptions apply e.g. real estate).
The purpose of signing (or initialing) a document is to provide evidence that you have seen and read it and agree to it - this only matters if at some time in the future a dispute arises about that. You could provide equivalent (possibly better) evidence by a thumbprint or impregnating DNA into the document.
Any "mark" can be your signature: illiterate people have historically used an X.