What is the meaning of when-issued (WI)?

New securities issues announced by the issuer but not yet sold or issued. Securities may be purchased or sold on a when-issued basis. Such trades are negotiated on a yield basis since price cannot be determined until the coupon rate is known. Price is usually calculated for delivery on the date of issue. Many U. S. Treasury securities are actively traded on a when-issued basis. Some corporate and municipal issues are also purchased on a when-issued basis. Purchasing or selling when-issued securities is a legitimate and acceptable practice that should not be confused with the related practice of when-issued trading. When-issued securities trading is the practice of agreeing to buy an about-to-be-issued security on or after the announcement of an offering and then selling the security before the date on which the securities are issued and must be paid for. Such transactions are regarded as trading activities by the banking regulators.