Things that persons under 18 are prohibited from doing include sitting on a jury, voting, standing as a candidate, buying or renting films with an 18 certificate or R18 certificate or seeing them in a cinema, being depicted in pornographic materials, suing without a litigant friend, being civilly liable, accessing adoption records and purchasing alcohol, tobacco products, knives and fireworks. The rules on minimum age for sale of these products are frequently broken so in practice drinking and smoking takes place before the age of majority; however many UK shops are tightening restrictions on them by asking for identifying documentation from potentially underage customers.