It is illegal in the District to refuse to rent someone an apartment on the basis of matriculation.

Matriculation? That's right. That is one of 16 categories that are protected against discrimination in housing in the District. It means landlords cannot keep out students just because they are students.

Republicans cannot be excluded, either. Or Democrats. There is a prohibition against discrimination based on political affiliation.

A landlord cannot deny housing because he doesn't like your looks -- no discrimination on the basis of "personal appearance," the law says.

The other, more familiar protected categories are race, color, religion, national origin, sex, age, marital status, sexual orientation, family responsibilities, physical handicap, source of income, place of residence or business and children.

The District has one of the broadest antidiscrimination laws in the country, housing experts say. It applies to both the rental and sale of housing, including condominiums, as well as the financing for these sales.

It is illegal to advertise a preference for a certain type of renter or buyer if the preference runs counter to the antidiscrimination code. And a landlord or seller may not say that an apartment or home is no longer available for rent or sale if it is.

Landlords may refuse to rent to persons who do not have the ability to pay or who have a history of creating disturbances, however. The total number of persons in an apartment may be limited to twice the number of bedrooms plus one (for example, five people in a two-bedroom unit) and to two persons in an efficiency.

The antidiscrimination law exempts some owner-occupied residences to let people be more selective if they are renting out space in their own homes, such as in rooming houses or English basements. Specifically, the exemption applies to owner-occupied residences with no more than two separate apartments rented out and up to five families who share a kitchen or bath with the owner. Children can be excluded from buildings that rent only to persons 60 years of age or older.

The D.C. Office of Human Rights has the authority to file a complaint and start an inquiry into alleged illegal discrimination. The Commission on Human Rights can hear the case and award punitive damages to the injured party if discrimination is found, said Roland Williams of the human rights office.

Williams advised that anyone who suspects they have been discriminated against illegally in the District should report the incident immediately to the Office of Human Rights at 727-3100.