ARTICLES EXPORTED AND RETURNED, NOT ADVANCED OR
IMPROVED IN CONDITION; ANIMALS EXPORTED AND RETURNED
Products of the United States when returned after having been
exported, without having been advanced in value or improved
in condition by any process of manufacture or other means
while abroad.....
Articles, previously imported, with respect to which the duty
was paid upon such previous importation or which were
previously free of duty pursuant to the Caribbean Basin
Economic Recovery Act or Title V of the Trade Act of 1974,
if (1) reimported, without having been advanced in value or
improved in condition by any process of manufacture or other
means while abroad, after having been exported under lease or
similar use agreements, and (2) reimported by or for the
account of the person who imported it into, and exported it
from, the United States........
Articles, previously imported, with respect to which the duty
was paid upon such previous importation if (1) exported
within three years after the date of such previous
importation, (2) reimported without having been advanced in
value or improved in condition by any process of manufacture
or other means while abroad, (3) reimported for the reason
that such articles do not conform to sample or specifications,
and (4) reimported by or for the account of the person who
imported them into, and exported them from, the United States...
Any aircraft engine or propeller, or any part or accessory of
either, previously imported, with respect to which the duty
was paid upon such previous importation, if (1) reimported
without having been advanced in value or improved in condition
by any process of manufacture or other means while abroad,
after having been exported under loan, lease or rent to an
aircraft owner or operator as a temporary replacement for an
aircraft engine being overhauled, repaired, rebuilt or
reconditioned in the United States, and (2) reimported by
or for the account of the person who exported it from the
United States...