Francis Scott Key would be dismayed if he had to write "The Star-Spangled Banner" in contemporary Washington -- especially that proud line "that our flag was still there." At two major local military reservations, it isn't.

Metro Scene last touched on this subject on Friday, reporting that one of the two flagpoles outside the Pentagon's river entrance was barren. Broken flag-raising equipment was blamed.

Yesterday, by the dawn's early light, with that pole still out of order, the flagstaff in front of Generals' Row that commands the heights of Fort Myer also lacked a flag. Unthinkable!

A call to the fort's military police office provided a logical answer. "The pole is being renovated," said the sergeant who answered the phone. "It's just today and tomorrow" -- that is, Saturday and Sunday. Flags in Abundance

This item, too, deals with flags, but of a different sort. You might title it "Seven Flags over Washington."

The Vista International Hotel in the 1400 block of M Street NW has three flagpoles and a policy of flying the homeland flag of any foreign visitor qualified for protocol honors. The management always checks with the State Department's protocol office.

Recently, for example, the flag of Mozambique (which includes a submachine gun in its design) flew while its president was staying there. This week will set some sort of record, hotel spokeswoman Diana Kaiser said, with seven such visitors, sometimes requiring the use of two of the flagpoles simultaneously. (The American flag always flies.)

This week's visitors getting the flag treatment will be the heads of state of Guinea-Bissau and Fiji, four government ministers from Zaire, the transportation minister of the Federal Republic of Germany, the minister of foreign affairs of Sudan, the wife of the Philippines' foreign minister, and Sri Lanka's minister of trade. Sorry, Wrong Number

Once again, this time in reporting the new dispute over VIP parking at National Airport, the news media (including this newspaper) have fallen into saying that "the 535 members of Congress" are eligible for free parking in the 100-space lot there. Even the usually fastidious Charles Osgood on CBS Radio repeated that mistaken number.

Mistaken? Yes. There are, at latest count, 540 members of Congress: 100 senators, 435 representatives, four delegates (from the District of Columbia, American Samoa, Guam and the Virgin Islands) and one resident commissioner (from Puerto Rico).

The delegates and the resident commissioner can't vote on the floor of the House, but they otherwise are full members of Congress with all the perquisites of office, including the right to free parking at National and Dulles airports.