What if they mention your religion or sexual orientation, disability, or even just age?
That's what you hope for but the ones who explicitly discriminate tends to be those who were put into management positions but never got management training. Anyone who got management training knows enough to keep quiet when they discriminate. Companies often pay some lawyer to hold discrimination training for their management teams. A manager can discriminate against your race by simply not hiring anyone for anything beyond blue collar work or not promoting anyone or giving them the worst hours, worst pay, or worst tasks but as long as they don't explicitly say it was because they don't like Asians, you really got no case.