Under age 20, a boy cannot be a monk- only novice. In Thailand they are called Samanen. Boys keep the Ten Precepts as their code of behavior, and are devoted to the Buddhist religious life during a break from secular schooling, or in conjunction with it if devoted to formal ordination.
The Ten Precepts are:
1.Refrain from killing living things.
2.Refrain from stealing....
3.Refrain from unchastity (sensuality, sexuality, lust).
4.Refrain from lying.
5.Refrain from taking intoxicants.
6.Refrain from taking food at inappropriate times (after noon).
7.Refrain from singing, dancing, playing music or attending entertainment programs (performances).
8.Refrain from wearing perfume, cosmetics and garland (decorative accessories).
9.Refrain from sitting on high chairs and sleeping on luxurious, soft beds.
10.Refrain from accepting money.