anchor.diff:      end,
       % Fun used to check if alias is valid
       InvalidAlias = fun() ->
  -        case re:run(Alias, ?ALIAS_VALIDATION_REGEXP) of
  -            {match, _} ->
  +        case Alias of
  +            ?EMPTY_ALIAS ->
                   false;
               _ ->
  -                case Alias of
  -                    ?EMPTY_ALIAS -> false;
  +                case re:run(Alias, ?ALIAS_VALIDATION_REGEXP) of
  +                    {match, _} -> false;
                       _ -> true
                   end
           end
  
positive.code: -spec set_alias(UserId :: onedata_user:id(), Alias :: binary()) ->
      ok | {error, disallowed_alias_prefix | invalid_alias | alias_occupied}.
  set_alias(UserId, Alias) ->
      % Fun used to check if alias has an disallowed prefix
      DisallowedPrefix = fun() ->
          case Alias of
              <<?NO_ALIAS_UUID_PREFIX, _/binary>> -> true;
  
negative.code:             {error, Reason} ->
                  % Alias not allowed, return error
                  {error, Reason};
              {ok, PossiblyUpdatedAlias} ->
                  NewUser = UserRecord#onedata_user{
                      name = proplists:get_value(name, Proplist, Name),
                      alias = PossiblyUpdatedAlias,
                      email_list = proplists:get_value(
                          email_list, Proplist, Emails),
                      connected_accounts = proplists:get_value(
  