As a knowledgeable professor of finance, it is important to understand the concept of minimum subscription in the context of an initial public offering (IPO). This refers to the minimum percentage of shares that a company must sell to the public by the date of the IPO closure. Currently, the minimum subscription requirement is set at 90%, as of October 27, 2021. Failure to meet this threshold may result in the cancellation of the IPO. Therefore, it is crucial for companies to carefully strategize and ensure sufficient interest from the public in their IPO.