1989 "Import" ban. Prevents the import of named (as "Non-Sporting") firearms, and later added a few more (loophole in 1989-early 1990 allowed the import of some that could be converted back to original characteristics--folding stock, flash hider, etc, after import).
Wouldn't affect (when the 1994 AW ban sunsets) the importation and "re-manufacture" as domestic (has to have 10 or fewer parts from a list the ATF puts out of foreign origin to be considered Domestically manufacured)--so, you could import HK 91 (German or Portuguese) receivers, a few other parts, and put a collapsable stock and flash hider on the rifle after the AW ban sunsets (as long as it has 10 or fewer foreign parts) and be legal. You would not be legal (since the 1989 Import ban has no sunset) to import the complete rifle or to have greater than 10 foreign made parts.
AFARR