§30. FORM OF ACCEPTANCE INVITED

(1) An offer may invite or require acceptance to be made by an affirmative answer in words, or by performing or refraining from performing a specified act, or may empower the offeree to make a selection of terms in his acceptance.

(2) Unless otherwise indicated by the language or the circumstances, an offer invites acceptance in any manner and by any medium reasonable in the circumstances.

Comments:

a. Required form. The offeror is the master of his offer.... The form of acceptance is less likely to affect the substance of the bargain than the identity of the offeree, and is often quite immaterial. But the offeror is entitled to insist on a particular mode of manifestation of assent....

b. Invited form. Insistence on a particular form of acceptance is unusual. Offers often make no express reference to the form of acceptance; sometimes ambiguous language is used. Language referring to a particular mode of acceptance is often intended and understood as suggestion rather than limitation; the suggested mode is then authorized, but other modes are not precluded.