Sometimes you can discriminate against a group of people -- if the particular job you are filling requires a person with specific characteristics.

In a very rare and narrow exception to antidiscrimination laws, you can discriminate against people on the basis of gender, religion, national origin, age or another protected characteristic (but never race) if the very nature of the job requires you to do so.

This exception -- called the bona fide occupational qualification (BFOQ) exception -- arises from the fact that some jobs require people who have certain characteristics that the law usually protects, such as people of a certain national origin or people of a certain religion.

For example, if you are a movie director searching for someone to play the role of Hamlet's mother, you can discriminate against men in filling the part. Or if you are an official in the Catholic Church, you can discriminate against non-Catholics when hiring priests.

In order to use this exception, you must prove that no member of the group that you want to discriminate against can perform the job. This can be a tough thing to prove, and courts often reject arguments that most employers would find perfectly legitimate. For example, the airlines can't discriminate against older applicants when hiring flight attendants simply because they think that passengers prefer young pretty faces. If you look at the actual job duties -- maintaining order in the plane's cabin, serving meals and beverages -- a 45-year-old is just as able to perform the job of flight attendant as a 25-year-old.

There are times, however, when an employer has no choice but to use the BFOQ exception. For example, the law has allowed BFOQs in the following instances:

• An employer was allowed to discriminate against women and hire only male attendants for its company bathroom.
• An airline was allowed to discriminate on the basis of religion and hire only Muslim pilots to fly certain routes in Saudi Arabia where Saudi Arabian law prohibited, under punishment of death, any non-Muslims to enter the area.