A tombstone is the term often used for the document announcing the launch of a public offering or structured-finance transaction. It is called a tombstone because the advertisement contains limited information typical of what is found on a gravestone: date of issuance, offering description, size, number of shares and some other basic details as required by the SEC.

The purpose of these tombstones is to provide the public with information about the offering, including the name of the issuing company, lead underwriters and financial advisor, offering price and sizes, the securities being offered, and the dates and allocations of the offering. A tombstone is the one way to alert potential investors that a company is making a wider offering, allowing them to make an informed decision if they'd like to participate.

Apart from providing the public with the necessary details, the tombstone also serves as Marketing/PRto potential investors. Companies use this opportunity to highlight the success of their previous offerings, as well as their achievements in the industry. By doing so, investors can gain insights regarding the track record of the company and decide if the investment is worth their risk.

The tombstone typically appears in the Wall Street Journal, major financial newspapers and websites, or in the New York Times. The tombstone isn't the only advertisement an issuer must have, though; most issuers are also required to publish a prospectus and a free writing prospectus. The free writing prospectus, which is uploaded to the SEC’s site, must contain much of the same information found in the tombstone advertisement, while the prospectus must include significantly more detail.

In summary, a tombstone is an advertisement printed in newspapers, magazines and other media, serving as pre-promotion and notification to investors about upcoming public offerings or structured-finance transactions. The ad contains minimal details about the offering, including the issuer, type of offering, size and other vital information as required by the Securities and Exchange Commission. By providing the public with the necessary information, tombstones allow potential investors to make an informed decision about any participating in an offering.