• When a tankling turns 13, they're considered as adults in the eyes of the law. Meaning, they can purchase alcohol, tabacco products, drive, and get married. But they still have to live with their parents or guardians until they turn 17, then they can leave the house. But if they get married, they can leave their parents if they want to. That's why Skittles can legally smoke. (Think about it, he's 13, if smoking at 13 was illegal, Skittles would be going to juvie) And Skittles can also legally marry if he wanted to because he's the age where Mars sees it as legal.
• Before the timeline of Infinity, tankwomen were treated as subclasses, they can not join the military and fly planes. They also had to get approval to do things from their husbands or if they're not married, their male family members. Tankwomen could only be nurses, doctors, teachers, bakers, chefs, cooks, waitresses, bartenders, baristas, busgirls, stockers, liberians, gardeners, mechanics, engineers, midwives, and scientists. Female tanklings were also not allowed to attend school. Tankwomen were expected to stay home and raise tanklings, if she wanted to work, she could only do the "non-heavy duty" jobs and she had to go through her husband or father, grandfather, brothers, male cousins, and uncles before doing so. However, after Infinity, Tankwomen were seen as equals and they could now join the military and fly planes if they wanted to. They could also work independently.
• Crossing the equator is a serious crime on Mars. (I truly believe the real cause of the war in Tankmen is racism and the arrow-helmet Tankmen are actually the military base of the southern hemisphere of Mars) It could lead to the death penalty.

(Under construction, more will be added later)