The standard notation for this class uses the number sign symbol, not the sharp sign from music, but it is pronounced "sharp P". More generally, the number sign may be used to denote the class of counting problems associated with any class of search problems. Jul 30, 2025 · number sign, versatile symbol (#) most commonly used to preface numbers (e.g., apartment #1) but which encompasses a variety of other uses, especially to tag (or hashtag) posts and messages on social media platforms. Each question is preceded by a number sign (#). If the first character in an entry is a number sign (#), the program treats the entry as a comment and ignores it. The number sign (#) is a typographical symbol that represents the word “number” in American English and in Canada. Generally placed immediately before a number or series of digits (with no spaces), it also is known by many other names and offers various other uses. Nov 7, 2017 · In computer code, the # symbol means that everything that follows is only comment, not instruction. Explore the meaning, origin, and various uses of the number sign (#), also known as the hash symbol or pound sign. Discover its significance in mathematics, social media, and computing. Feb 6, 2020 · The "#" symbol has many names: number sign, hash sign, pound sign, octothorpe. But when should you use it in your writing? Check out our blog to find out. Discover the Number Sign # character. Find its Unicode, HTML representation, and learn how to easily copy and paste it into your documents. A hashtag is a metadata tag operator that is prefaced by the hash symbol, #. On social media, hashtags are used on microblogging and photo-sharing services–especially Twitter and Tumblr –as a form of user-generated tagging that enables cross-referencing of content by topic or theme. [1] . Mar 25, 2025 · Describes guidelines to use the number sign ' (\#)' in Microsoft documents and provides examples.