Because of the special nature of the relationship between the District of Columbia and the federal government, D.C. tax laws contain special provisions not found in the 50 states.

These special provisions exempt people in three categories from District income tax:

* An elected officer of the U.S. government.

* An officer of the Executive Branch of the U.S. government who was appointed by the president subject to confirmation by the Senate and whose appointment may be terminated at the pleasure of the president.

(The exemption does not apply to a member of this group who was a legal resident of the District on the last day of the tax year.)

* A person on the personal staff (not a committee staff) of an elected member of the Legislative Branch if a bona fide resident of the same state as that elected member.

Everyone in this category is required to file an information return by April 15, 1982, on Form D-100. Others who are exempt from D.C. tax under these provisions may file Form D-40B to claim a refund of any D.C. tax withheld from pay. Military Personnel

If you are a legal resident of Maryland, Virginia or the District of Columbia, you don't lose that status when living elsewhere because of duty assignment.

You are subject to income tax and required to file a resident return in your state of domicile regardless of where you are stationed.

Conversely, if you are a legal resident of another state, you are not subject to income tax in any of the three local jurisdictions solely because you are assigned to military duty there.

So unless you are a legal resident of Maryland or Virginia, you are not required to report or pay tax on military income. But you are liable for reporting, as a nonresident, income earned from other sources within the state (a moonlighting civilian job, for example).

The District laws are more liberal. If you are a member of the military living in D.C. but claiming legal residence elsewhere, you need not report or pay tax on any income regardless of source.

The husband or wife of a member of the armed forces is considered a resident or nonresident according to the general rules in each state without regard to the military status of the spouse.