We prove that the standard norm varieties for Milnor symbols mod
of
length
are birationally isomorphic to Pfister quadrics when
, to Severi–Brauer
varieties when
and
,
and to varieties defined by reduced norms of cyclic algebras when
and
. In the
case
and
the case
and ,
the results imply that the standard norm varieties for two equal Milnor symbols mod
are
birationally isomorphic, and we conjecture this in general.