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 ordered the suspension of his country’s special rules for “de minimis” merchandise from China and Hong Kong.

Friday saw the president reopen the floodgates for millions of duty-free shipments from e-commerce firms like Shein and Temu.

Ending tariff exemptions on low-cost packages from China has broad bipartisan support in Washington, and Trump pulled the plug when he raised tariffs on Chinese goods by 10% earlier this week. Goods sent through duty-free packages became subject not only to existing tariffs — 25% for many Chinese products — but also the new 10%.