man ‧ da ‧ to ‧ ry /ˈmændət ə ri $ -tɔːri/ BrE AmE adjective
if something is mandatory, the law says it must be done SYN compulsory , obligatory ⇨ discretionary
mandatory for
Crash helmets are mandatory for motorcyclists.
Murder carries a mandatory life sentence.
The Council has made it mandatory for all nurses to attend a refresher course every three years.