covered Unicode currently covers most major writing systems in use today. , a total of 161 scripts are included in the latest version of Unicode (covering alphabets, abugidas and syllabaries), although there are still scripts that are not yet encoded, particularly those mainly used in historical, liturgical, and academic contexts. Further additions of characters to the already encoded scripts, as well as symbols, in particular for mathematics and music (in the form of notes and rhythmic symbols), also occur. The Unicode Roadmap Committee (Michael Everson, Rick McGowan, Ken Whistler, V.S. Umamaheswaran) maintain the list of scripts that are candidates or potential candidates for encoding and their tentative code block assignments on the Unicode Roadmap page of the Unicode Consortium website. For some scripts on the Roadmap, such as Jurchen and Khitan small script, encoding proposals have been made and they are working their way through the approval process. For other scripts, such as Mayan (besides numbers) and Rongorongo, no proposal has yet been made, and they await agreement on character repertoire and other details from the user communities involved. Some modern invented scripts which have not yet been included in Unicode (e.g., Tengwar) or which do not qualify for inclusion in Unicode due to lack of real-world use (e.g., Klingon) are listed in the ConScript Unicode Registry, along with unofficial but widely used Private Use Areas code assignments. There is also a Medieval Unicode Font Initiative focused on special Latin medieval characters. Part of these proposals have been already included into Unicode. Script Encoding Initiative The Script Encoding Initiative, a project run by Deborah Anderson at the University of California, Berkeley was founded in 2002 with the goal of funding proposals for scripts not yet encoded in the standard. The project has become a major source of proposed additions to the standard in recent years. Versions The Unicode Consortium and the International Organization for Standardization (ISO) have together developed a shared repertoire following the initial publication of The Unicode Standard in 1991; Unicode and the ISO's Universal Coded Character Set (UCS) use identical character names and code points. However, the Unicode versions do differ from their ISO equivalents in two significant ways. While the UCS is a simple character map, Unicode specifies the rules, algorithms, and properties necessary to achieve interoperability between different platforms and languages. Thus, The Unicode Standard includes more information, covering—in depth—topics such as bitwise encoding, collation