Bona Fide Occupation Qualification (BFOQ)
An example of a BFOQ is that Chinese restaurants can argue they have a legitimate reason for hiring only Asians to work in their restaurants. Other examples can be found in the mandatory retirement ages for bus drivers and airline pilots, which are required for safety reasons.
It is important to know this term because you may come across it, after confronting an employer about a potentially discriminatory practice. If your employer does claim that it is not discriminating against you because there is a BFOQ related to your job, you can question that defense because it is the employer’s responsibility to prove BFOQs are "reasonably necessary" and that there is no reasonable alternative with a lesser impact on the protected classes (e.g., minorities, women, the disabled, etc.).