A Latin term that’s been little-known outside the world of customs brokers has suddenly become the stuff of headlines. Along with imposing new 10% tariffs on all Chinese imports as of Feb. 4, US President Donald Trump suspended his country’s special rules for “de minimis” merchandise from China and Hong Kong.

The trade loophole is meant to ease small-scale sales — but critics say it's been abused and gives Chinese firms an unfair advantage.

U.S. President Donald Trump this week shut a trade loophole that has been used to ship low-value packages duty-free from China, the "de minimis" exemption on import tariffs. Trump's halt to Section 321 de minimis is part of his implementation of an additional 10% tariff on China and 25% tariffs on Canada and Mexico,

Move followed US introduction of tariffs on Chinese imports and removal of long-standing duty-exemption rule, but is no longer in effect

The change comes after President Donald Trump announced new tariffs that also target a popular trade loophole, called "de minimis."

USPS said the change will not impact the flow of letters and 'flats' from China and Hong Kong. It did not immediately comment on whether this was tied to Trump's change to ending de minimis shipments.