Mandatory
1. Mandatory, Compulsory, Required : لازمی : Required by rule.
In most schools physical education is compulsory.
Attendance is mandatory.+ More
Obligatory - morally or legally constraining or binding.
Compulsory, Mandatory, Required - لازمی - required by rule; "in most schools physical education is compulsory".
Convention, Formula, Normal, Pattern, Rule - روایت - something regarded as a normative example; "the convention of not naming the main character".