Bread-Bakers v097.n048.12

In reading info re' flour mills I have noticed that some of them have a
statement saying "no popcorn" when discissing what grains can be processed.
I have used popcorn to make cornmeal for 30 years and have found it very
satisfactory as well as easily available. Does anyone know why there would
be this kind of exclusion?

Carolyn