Capital sharp s (ẞ) is the 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 word-initially in German text, and traditional German printing (which used blackletter) never used all-caps. When using all-caps, traditional spelling rules required the replacement of ß with SS. However, in 2010, the use of the capital ẞ became mandatory in official documentation in Germany 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 later 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.