RFC  3023, include  both types :

   3.   XML Media Types  . . . . . . . . . . . . . . . . . . . . . .   5
   3.1  Text/xml Registration  . . . . . . . . . . . . . . . . . . .   7
   3.2  Application/xml Registration . . . . . . . . . . . . . . . .   9