All,
The developer team at Wikimedia is making some changes to how accounts work, as part of our on-going efforts to provide new and better tools for our users (like cross-wiki notifications). These changes will mean users have the same account name everywhere, will let us give you new features that will help you edit & discuss better, and will allow more flexible user permissions for tools. One of the pre-conditions for this is that user accounts will now have to be unique across all 900 Wikimedia wikis.[0]
Unfortunately, some accounts are currently not unique across all our wikis, but instead clash with other users who have the same account name. To make sure that all of these users can use Wikimedia's wikis in future, we will be renaming a number of accounts to have "~” and the name of their wiki added to the end of their accounts' name. This change will take place on or around 27 May. For example, a user called “Example” on the Swedish Wiktionary who will be renamed would become “Example~svwiktionary”.
All accounts will still work as before, and will continue to be credited for all their edits made so far. However, users with renamed accounts (whom we will be contacting individually) will have to use the new account name when they log in.
It will now only be possible for accounts to be renamed globally; the RenameUser tool will no longer work on a local basis - since all accounts must be globally unique - therefore it will be withdrawn from bureaucrats' tool sets. It will still be possible for users to ask on Meta for their account to be renamed further, if they do not like their new user name, once this takes place.
A copy of this note is posted to meta [1] for translation. Please forward this to your local communities, and help get it translated. Individuals who are affected will be notified via talk page and e-mail notices nearer the time.
[0] - https://meta.wikimedia.org/wiki/Help:Unified_login [1] - https://meta.wikimedia.org/wiki/Single_User_Login_finalisation_announcement
Yours, -- James D. Forrester Product Manager, VisualEditor Wikimedia Foundation, Inc.
jforrester@wikimedia.org | @jdforrester