A picture to understand the safe withdrawal methods in the cryptocurrency circle. The difference between U-card and traditional OTC Recently, many of my friends' out of town funds have been illegally deposited, frozen, unscrupulous, undervalued by cryptocurrency merchants, or paid on behalf of others. They have also been contaminated by small mixed funds from pig killing disks. I have prepared a logic for withdrawal/consumption of U-cards for my friends today, which is worth recommending as a supplementary solution to traditional OTC.