Wikipedia:Diacritical marks

The modified letters Ä, Ö and Ü on a German keyboard

The correct use of diacritical marks is considered by many editors an important part of writing an encyclopedia. Under the Wikipedia:Manual of Style § Spelling and romanization guidelines, "The use of diacritics for foreign words is neither encouraged nor discouraged; their usage depends on whether they appear in verifiable reliable sources in English". The current Wikipedia practice on this issue is generally in line with other English-language encyclopedias such as Britannica, and with the recommendations of influential style guides such as The Chicago Manual of Style. Particular care is taken to spell personal names correctly. In some other cases, such as with loanwords, the common spelling in other English sources is normally used.

Several reasons for the current practice have been presented in addition to external guides and practice: Accuracy (the lack of diacritics in foreign names is considered a grammatical error or misspelling by several reliable sources), consistency (following the "house style" instead of case-by-case use of the most common spelling), harmlessness (the diacriticless spelling is deducible from the proper noun, but not vice versa), pronunciation guidance, informativeness (an encyclopedia's primary purpose is to educate the readers by providing accurate, complete and trustworthy information) and respect (particularly with living people, knowingly misspelling a name could be both unencyclopedic and unethical).