Translations:Nick Character Sets/3/en

Important notes
A few notes:
 * The following basic nick characters are always allowed/included: a-z A-Z 0-9 [ \ ] ^ _ - { | }
 * Some combinations can cause problems and will cause an error. For example, combining latin* and chinese-* can not be properly handled by the IRCd and UnrealIRCd will refuse it. Mixing of other charsets might cause display problems. UnrealIRCd will print out a warning if you try to mix latin1/latin2/greek/other incompatible groups.
 * Most Services do not permit registration of UTF8 nicks
 * Casemapping (if a certain lowercase character belongs to an upper one) is done according to US-ASCII, this means that characters like &#246; and &#214; are not recognized as 'the same' and hence someone can have a nick with &#225;lpha and someone else &#193;lpha at the same time. This is a limitation of the current system and IRCd standards. Work is underway at the IRCv3 working group to solve this. People should be aware of this limitation. Note that this limitation already existed in channels (in which nearly any characters have always been available for use, and casemapping was also always performed in US-ASCII).
 * There is also no "similar looking character" or "identical looking character" checking. In particular if you enable cyrillic script (eg: russian-utf8) then characters such as cyrillic A and latin A will look the same. This could be abused to impersonate another user by using the identical looking character.