Many European languages have more characters than the standard 26 letters of the Latin alphabet, and include "diacritical signs", such as, for French:
é
è
ê
ë
ï
ü
ç
à
ù
Users are likely to want to include such diacritical signs in their Pseudonyms, without even realising that the usage of such diacritical signs is not evident in other languages.
I suggest to forbid these diacritical signs in Pseudonyms.
Justification
If the diacritical sign is absent from a user's keyboard (= the general case), then that user cannot research another one via the search function. This may impede communication between members of the Community that do not share the same language.
Additionally, the usage of diacritical signs would enable two members of the Community to have Pseudonyms that differ only by the presence or not of that diacritical sign, which will be easily visible by the locutors of the language where this diacritical sign exists, but hardly by the others.
Finally, there is a possibility that some diacritical signs do not display properly on the user's screen, if the coding system for characters for display is not the same as for the storage of the Pseudonym.
Many European languages have more characters than the standard 26 letters of the Latin alphabet, and include "diacritical signs", such as, for French:
Users are likely to want to include such diacritical signs in their Pseudonyms, without even realising that the usage of such diacritical signs is not evident in other languages.
I suggest to forbid these diacritical signs in Pseudonyms.
Justification