In 2016, the Council for German Orthography proposed the introduction of optional use of ẞ in its ruleset (i.e. variants STRASSE vs. STRAẞE would be accepted as equally valid). The rule was officially adopted in 2017. In Germany and Austria, the letter ß is present on computer and typewriter keyboards, normally to the right on the upper row. The German typewriter keyboard layout was defined in DIN 2112, first issued in 1928. In other countries, the letter is not marked on the keyboard, but a combination of other keys can produce it. Often, the letter is input using a modifier and the "s" key. The details of the keyboard layout depend on the input language and operating system, such as Ctrl+Alt+s, on some keyboards such as US-International also AltGr+s in Microsoft Windows or Option+s on the US, US-Extended, and UK keyboards in macOS. In Windows, one can also use alt code 0223. Some modern virtual keyboards show ß when the user presses and holds the s key. The HTML entity for ß is codice_1. Its code point in the ISO 8859 character encoding versions 1, 2, 3, 4, 9, 10, 13, 14, 15, 16 and identically in Unicode is 223, or DF in hexadecimal. In TeX and LaTeX, codice_3 produces ß. A German language support package for LaTeX exists in which ß is produced by codice_4 (similar to umlauts, which are produced by codice_5, codice_6, and codice_7 with this package). In modern browsers, "ß" will be converted to "SS" when the element containing it is set to uppercase using codice_8 in Cascading Style Sheets. The JavaScript in Google Chrome will convert "ß" to "SS" when converted to uppercase (e.g. codice_9). In the orthography of the German spelling reform of 1996, both "ß" and "ss" are used to represent between two vowels in Standard German, as follows:  Thus it helps to distinguish words like ('penance, fine': long vowel) and ('buses': short vowel). It is also consistent with the general rule of German spelling that a doubled consonant letter serves to mark the preceding vowel as short (the consonant sound is never actually doubled or lengthened in pronunciation).