Mandatory and imperative

English as a Second Language English Vocabulary, Grammar and Idioms
1

Hi,

I would like to know the usage difference between mandatory and imperative.

Himanshu.

2

for my liking mandatory is quite formal.
it’s also used in ITC.

imperative
[url]http://dictionary.cambridge.org/define.asp?key=39320&dict=CALD[/url]
can be adj or noun