“…We shall prove some results for general k and later specialize to global fields to get more complete results applying a theorem of Margulis [2]. In contrast with the case of global fields, it was proved in [7] that, if K is a function field in one variable over a number field, and if D is an algebra with center K and with an involution of the second kind, the group SU (1, D)/[U (1, D), U (1, D)] can be infinite in general; we gave an infinite class of such examples. We believe that the results of this note would be known to experts but it has not been set down in print.…”