Which of these documents falls within the definition of “prospectus” in section 2(70) of the Companies Act, 2013?

Section 2(70) of the Companies Act, 2013 defines a prospectus as any document described or issued as a prospectus, and expressly includes any notice, circular, advertisement or other document inviting offers from the public for the subscription or purchase of securities, as well as red herring and shelf prospectuses. A private placement offer letter under section 42 goes only to identified persons, not the public, so it is not a prospectus.