ß
The glyph ß is a ligature of ſ (long s) and s or z that has become a distinct letter in the German alphabet; its German name is Eszett (IPA /ɛsˈtsɛt/) or scharfes S (sharp S). In German orthography, the letter alternates with ss under certain conditions, and it is replaced by ss when there is no ß available. ß is nearly unique among the letter of Latin alphabet in that it has no upper case form since it never occurs initially (one of the few other examples is kra, used in Greenlandic).
Origin
There are two different origins of the ligature ß:
- Ligature ſs: a ligature of long s (ſ, looks like an f without the bar) and (normal) round s.
- Ligature ſz: a ligature of ſ and z.
The ligature of long ſ and round s was used in antiqua typefaces, for instance in English or French. It fell into disuse when the long ſ was abandoned in the 18th century.
In German blackletter typefaces, the ligature of long ſ and z was used since the Middle Ages. In the High German consonant shift, Germanic [t] became [s] or [ts]. At first, both were spelled zz, but soon, they were differentiated as ſz and tz. Originally, that s-sound was different from the old Germanic s-sound spelled ss, but this difference was lost in the Middle Ages. Therefore, the spellings ſz and ss became confused. The modern distinction between the two spellings emerged after many centuries. Until the German spelling reform of 1901, the use varied from region to region.
The usual typeface for German was blackletter. In the late 18th and early 19th century, when more and more German texts were printed in antiqua, the typesetter looked for an antiqua counterpart of the blackletter ſz ligature because they wanted to preserve the common distinction between ſz and ss. The preservation of this difference in antiqua typefaces became obligatory with the German spelling reform of 1996.

There have been four different typographical solutions for the form of the antiqua ß:
- letter combination ſs (not as a ligature, but as a single type),
- ligature of ſ and s,
- ligature of ſ and ʒ, a kind of blackletter z (blackletter z looks similar to a "3"; this solution is closest to the original blackletter ligature),
- a ligature ſ and a kind of 3 so that the ligature resembles a Greek β (a compromise of the second and the third solution).
Currently, most antiqua ß are shaped according to the second or the fourth solution. The first and third solution are seldom found. The typographer Jan Tschichold claimed that the German blackletter ß originated as a ligature of ſ and s. His view is widespread, even though historical linguists say that there's no argument to support it. Tschichold's claim is based on a picture drawn by himself that illustrates how blackletter ſ and s melt together, and on a reference to the ſs-ligature in antiqua. A historical specimen of the former has never been found, and the latter is unrelated to the origin of the German blackletter ſz ligature.


Usage
In today's German orthography, “ß” is used to denote a voiceless “s” (IPA sound [s]) at the beginning of a syllable (e.g. “Stra-ße” (= street)) or after a long vowel if other words of the family have it (e.g., es fließt (“it flows”) because of flie-ßen (“to flow”)) whereas “ss” is used if the s sound belongs to two syllables (e.g., ge-flos-sen (“floated”, past participle)) or after a short vowel if other words of the family use a double s (e.g., es floss (“it floated”)).
Older usages and spelling reform
Before the German spelling reform of 1996, there was an additional rule that “ss” could only be used if bridging two syllables and must otherwise be replaced by “ß”, even if it follows a short vowel. As a result, floss was formerly spelled floß, and the spelling Floß was ambiguous between a capitalised floss (with short vowel) and the noun Floß (with long vowel -- all nouns are capitalised in German).
The spelling reform also affected certain place names, e.g. "Rußland" (Russia) became "Russland" and "Preßburg" (Bratislava) became "Pressburg"; the English and French used Pressburg as the name of the city anyway, until the use of Bratislava became common in the decade after the independence of Czechoslovakia.
Switzerland and Liechtenstein
Switzerland and Liechtenstein gradually abolished the use of "ß" since the 1930s. This change coincided with the increased use of typewriters; Swiss machines contained accented French letters (ç, à, é, è) as well as German umlauts (ü, ä, ö), and consequently had no key to spare for ß. In 1974, the Neue Zürcher Zeitung was the last Swiss newspaper to give up the ß. Today, ss is always used instead of ß in schools, correspondence or newspapers, a convention that was confirmed by the German spelling reform of 1996. However, major Swiss publishing houses for books use ß since they address the entire German speaking market.
Replacement and all-upper-case
If no ß is available, ss is used instead. This ss may be hyphenated (e.g. Stras-se 'street'; compare Stra-ße).
The letter has no capital form and never appears intially. If an entire word is capitalized, SS is used, e.g., STRASSE. Excepted are legal documents, where capitalized names may retain an ß to prevent ambiguity, e.g., HANS STRAßER.
In the old orthography, the Duden encouraged the use of SZ in cases where SS would produce an ambiguous result, as with "IN MASZEN" (in limited amounts; "Maß"=measure) vs. "IN MASSEN" (in massive amounts; "Masse"=mass). The number of such cases was so small that this rule was more confusing than helpful, thus it has been dropped. Only in the German military the capitalization SZ is still in occasional use, even when there's no ambiguity - e.g. boxes inscribed "SCHIESZGERÄT" (shooting material) can still be found here and there. The same is true for architectural drawings, which are often using capital letters and where both "MASZE" and "MASSE" are quite frequent. sz is also still used for ß in military teletype operation within Germany.

There have been repeated attempts to introduce an upper case ß. One of the best known examples is the Eastern German 1957 Duden. A recent proposal to the Unicode Consortium for capital double s by Andreas Stötzner was rejected in 2004, on the basis that capital ß is a typographical issue, and therefore not suitable for character encoding.
ß and β
"ß" should not be confused with the lowercase Greek letter beta ("β"), which it closely resembles, particularly to the eyes of non-German readers, but to which it is unrelated. Indeed the resemblance is not close enough to enable substitution of the one with the other in typeset material without the result looking extremely unprofessional, comparable to substituting lowercase Greek letter omega ("ω") for "w" in English text. Any typeset material should use the ß; where that letter is unavailable, the substitution "ss" for "ß" is correct.
The differences between "ß" and "β" in most typefaces are
- β reaches below the line while ß does not, except in handwriting
- β connects the vertical part on the left with the end of the horizontal near the bottom; ß does not.
- β uses Greek rules of stroke thickness (slanted strokes are thinnest), ß uses Latin rules (horizontal strokes are thinnest).
- β is often slightly slanted to the right even in upright fonts, while ß is exactly vertical.
However, such substitution once was common when describing beta test versions of application programs for older operating systems, such as classic Mac OS, whose character encodings did not support easy use of Greek letters. Also, the original IBM DOS codepage, CP437 (aka OEM-US), conflates the two characters, assigning them the same codepoint (0xE1) and a glyph that minimises their differences.
Also note that in German handwriting, the ß is written very similar to β, slightly slanted and reaching below the line.
Miscellaneous
When ordering German words alphabetically, the collation rules say that "ß" should be treated as if it were a double "s". So, for example: "Ruß" < "Russe" < "rußen" < "Russland". Some people sort "ß" like a single "s", but this is incorrect.
In text processing contexts, the "ß" is sometimes associated with the umlaut, for a purely practical reason: both the "ß" and true umlauts (ä, ö, ü) are not in ASCII. Thus they tend to cause the same kinds of problems in all sorts of digital text processing applications. Historically, the development of "ß" is not related with the umlauts, and they are not associated outside of text processing contexts.
The ß is also used by some in romanizing the Sumerian language, in which it represents sh. Some Sumerian scholars use sz or $ instead.
The ß character is popular in Hungarian "text speak" used with mobile phones, replacing the grapheme sz, thus using one letter fewer in the SMS. Many Swiss Germans also use it for any ss in SMS.
The HTML entity for "ß" is ß
.
Its codepoint 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.
On Windows computers with an American keyboard, the ß can be typed by holding Alt, typing either 0223 or 225 on the right number pad, and then releasing Alt (depending on the selected input language and on the code page)*. On Macintosh computers with an American keyboard, the ß can be typed by holding Option [Alt] and pressing the "s" key. On X-based systems, ß can be entered in numerous ways depending on the keyboard layout. Commonly, pressing AltGr + s or typing Compose, s, s works. The Vim digraph is ss.
- On European keyboards only holding Alt and pressing "0223" in sequence works. That is, assuming the keyboard does not have ß on it already.