|This article may be expanded with text translated from the corresponding article in the German Wikipedia. (April 2010)|
Capital sharp s (ẞ) is the contestable majuscule of eszett. Sharp s is unique among the letters of the Latin alphabet in that it has no traditional upper case form. This is because it never occurs initially in German text, and traditional German printing (which used blackletter) never used all-caps. When using all-caps, current spelling rules require the replacement of ß with SS. However, in 2010 the use of the capital sharp s became mandatory in official documentation when writing geographical names in all-caps.
There have been repeated attempts to introduce a majuscule ß. Such letterforms can be found in some old German books dating back to the late 19th century and some modern signage and product design. One of the best known examples is the East German 1957 Duden.
Inclusion in Universal Character Set 
A proposal by Andreas Stötzner to the Unicode Consortium for the inclusion of capital double s in the Universal Character Set was rejected in 2004, on the basis that capital ß is a typographical issue, and therefore not suitable for character encoding. A reworked version of Stötzner's proposal was submitted on 25 April 2007 by DIN. The proposal suggested the Unicode name LATIN CAPITAL LETTER SHARP S. The proposal has been adopted and the character was added as Unicode character "ẞ" U+1E9E LATIN CAPITAL LETTER SHARP S when Unicode 5.1 was released, on 4 April 2008.
Support in computer operating systems 
In Microsoft Windows the Capital Sharp S is included in system fonts such as Arial, Times New Roman, Courier New, Segoe UI, Tahoma and Verdana since Windows 7. On Mac OS X 10.6 and 10.7 only one Apple font includes it, Geneva Regular. But depending on the software, the fallback mechanism will likely show the font from a different typeface such as Arial. Until the current iOS version there is no official support.
Glyph designs 
A number of designs have been proposed for the Versal-Eszett, all based on the origins of the lowercase ß as a ligature of a long s and a round z, but applying those principles to the design of uppercase rather than lowercase letters.
The most common is the design used on the cover of Signa magazine, which joins an ascender made from an inverted capital U to an ezh-like partial capital letter Z. Another similar design uses the ascender of a capital letter 'F' instead of the inverted U ascender. A radically different design that still reflects the same typographic history consists of two capital letters S joined by a short stroke at the top to form a ligature.
As of April 2008[update], typographers have yet to agree on a standard form for the letter capital ẞ, as they did in 1903 when an association of German printers and type foundries agreed on the "Sulzbacher Form" as standard for the lowercase ß.
- Institut für Deutsche Sprache. "Empfehlungen des Rats für deutsche Rechtschreibung, Teil 1: Regeln und Wörterverzeichnis" [Recommendations of the Council for German Orthography, Part 1: Rules and List of Words] (pdf) (in German). Retrieved 2012-02-09. "Steht der Buchstabe ß nicht zur Verfügung, so schreibt man ss.. . . Bei Schreibung mit Großbuchstaben schreibt man SS, zum Beispiel: Straße – STRASSE"
- (German) Empfehlungen und Hinweise für die Schreibweise geographischer Namen, 5. Ausgabe 2010
- Proposal to encode Latin Capital Letter Double S (rejected)
- Proposal to encode Latin Capital Letter Sharp S to the UCS
- Unicode chart
Further reading 
- Das große Eszett. In: Signa, Heft Nr. 9. Edition Waechterpappel, Grimma 2006, ISBN 3-933629-17-9. (in German)