Mail order credit
A mail order credit is a revolving credit. When you buy something from a mail order company, you can often pay in installments. You can also buy stuff for a maximum amount that you agree in advance. When you have paid back some money, you can buy stuff again up to the amount you have agreed.
You often have to pay a lot of interest for this loan. This interest is almost as high as the legal maximum interest. The legal maximum interest is the highest interest that a financial company is allowed to charge.