mandatory Antonyms

not needed unimportant volunteer voluntary volitional unessential trivial trifling self-imposed irrelevant unnecessary uncoerced not obligatory uncompensated non-compulsory unneeded elidable unforced nonmandatory incidental secondary optional nonessential discretionary discretional banned auxiliary arbitrary arbitral ancillary adventitious dispensable elective frivolous negligible needless minor insignificant inessential inconsiderable inconsequential immaterial accidental