  Fix a symbol $\underline{a}$ in the mod-$\ell$ Milnor $K$-theory of a field
$k$, and a norm variety $X$ for $\underline{a}$. We show that the ideal
generated by $\underline{a}$ is the kernel of the $K$-theory map induced by
$k\subset k(X)$ and give generators for the annihilator of the ideal. When
$\ell=2$, this was done by Orlov, Vishik and Voevodsky.
