In an IPO, RHP stands for Red Herring Prospectus, which is a document filed with the market regulator SEBI by a company when it intends to raise funds from the public. The RHP contains key information about the operations and future prospects of the company, including details about the total number of shares offered through the fresh issue, offer for sale, and the utilization of funds being collected, apart from other details pertinent to the company. The RHP has to be filed with the registrar of companies at least three days prior to the IPO issue opening. The DRHP, or Draft Red Herring Prospectus, is a preliminary version of the RHP that is filed with SEBI before the IPO, and the IPO is subject to SEBI approval. SEBI gives its approval in the form of observations and may at times even recommend changes in it. Once such changes are incorporated into the DRHP, the final version becomes the RHP. The main difference between DRHP and RHP is that DRHP is not an official offer to sell the security, while the final prospectus is an official document and includes the price of the sold securities.