The categories of express consignments are as below:

Import: 
X1 Documents
X2 Low-value Non-Dutiable, DPV not more than TWD 2,000
X3 Low-value Dutiable, DPV between TWD2,001~50,000
X4 High-value Dutiable, DPV above TWD 50,000

Export: 
X6 Documents
X7 Low-value, FOB not more than TWD50,000
X8 High-Value, FOB above TWD50,000