Technical standards can also form a trade barrier.
Tips
usage
Chinese economic writing splits trade barriers into two: 关税壁垒 (tariff barriers) and 非关税壁垒 (non-tariff barriers - quotas, technical standards, licensing, anti-dumping measures). 壁垒 is literally a 'defensive wall', very visual.
memory
壁 (wall) + 垒 (rampart / fortification). Picture a medieval wall around a city: 贸易壁垒 is the economic equivalent, everything a country stacks up to keep imports out.
