wikipedia :
As no words start with double s or ß, no uppercase ß (ẞ) is necessary.
However, not every ss can be written as ß. German often puts two or more words together to make a longer word. If the new word has ss, it cannot be written as ß. For example, Voßstraße is two words joined together (Voß and straße). It can also be written as Vossstraße but not as Vosßtraße because sstraße (or ßtraße) is not a word, and the ß is in the word Voss (Voß).
another rule :When the preceding vowel is short, as in Fluss, ss is used. However, the ß is used when the preceding vowel is long as in Straße.
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Deutsch… bleach!!!
Would this make ä = æ, ö = ø, and å = aa as well?
wikipedia :
As no words start with double s or ß, no uppercase ß (ẞ) is necessary.
However, not every ss can be written as ß. German often puts two or more words together to make a longer word. If the new word has ss, it cannot be written as ß. For example, Voßstraße is two words joined together (Voß and straße). It can also be written as Vossstraße but not as Vosßtraße because sstraße (or ßtraße) is not a word, and the ß is in the word Voss (Voß).
another rule :When the preceding vowel is short, as in Fluss, ss is used. However, the ß is used when the preceding vowel is long as in Straße.