TrueDoc is an outline font standard developed by Bitstream that compactly encodes fonts for use in web pages through their TrueDoc system. Embedding a typeface in this way has the aim of eliminating graphics sometimes used in headings or other text, and replacing them by standard text, styled via CSS. The font files are made small by use of subsetting (only including the needed characters), and only need to be downloaded once. It is a secure method, in that fonts can only be used for the pages they were intended for, and not on other sites, or in other applications.