The Swedish alphabet is a 29-letter alphabet, using the 26-letter ISO basic Latin alphabet plus the three additional letters Å/å, Ä/ä, and Ö/ö constructed in the 16th century by writing “o” and “e” on top of an “a”, and an “e” on top of an “o”. Though these combinations are historically modified versions of A and O according to the English range of usage for the term diacritic, these three characters are not considered to be diacritics within the Swedish application, but rather separate letters, and are as independent letters following z. Before the release of the 13th edition of Svenska Akademiens ordlista in April 2006, w was treated as merely a variant of v used only in names (such as “Wallenberg”) and foreign words (“bowling”), and so was both sorted and pronounced as a v. Other diacritics (to use the broader English term usage referenced here) are unusual in Swedish; é is sometimes used to indicate that the stress falls on a terminal syllable containing e, especially when the stress changes the meaning (ide vs. idé, “winter lair” vs. “idea”) as well as in some names, like Kastrén; occasionally other acute accents and, less often, grave accents can be seen in names and some foreign words. The letter à is used to refer to unit cost (a loan from the French), equivalent to the at sign (@) in English.
The German ü is treated as a variant of y and sometimes retained in foreign names and words, e.g. müsli (“muesli/granola”). A proper diaeresis may very exceptionally be seen in elaborated style (for instance: “Aïda”). The German convention of writing ä and ö as ae and oe if the characters are unavailable is an unusual convention for speakers of modern Swedish. Despite the availability of all these characters in the Swedish national top-level Internet domain and other such domains, Swedish sites are frequently labelled using a and o, based on visual similarity (mainly to avoid lingering technical problems with the use of characters which are outside of the limited 7-bit ASCII set).
In Swedish orthography, the colon is used in a similar manner as in English, with some exceptions: the colon is used for some abbreviations, such as 3:e for tredje (“third”) and S:t for Sankt (“Saint”), and for all types of suffixes that can be added to numbers, letters and abbreviations, such as a:et (“the a”) and CD:n (“the CD”).