Union label
（重定向自Union bug）
A union label (sometimes called a union bug) is a label, mark or emblem which advertises that the employees who make a product or provide a service are represented by the labor union or group of unions whose label appears, in order to attract customers who prefer to buy union-made products. The term "union bug" is frequently used to describe a minuscule union label appearing on printed materials, which supposedly resembles a small insect.