.Id_str( str{} ){}
  {
    unsigned    id;

    id = .Id();
    str{0} = 'a' + (id>>12)&$F;
    str{1} = 'a' + (id>>8 )&$F;
    str{2} = 'a' + (id>>4 )&$F;
    str{3} = 'a' + (id>>0 )&$F;
    str{4} = '*0';
    return( str );
  }
