Obligatory

прилагательное 1) непременный, обязательный Синоним(ы): compulsory 2) обязывающий

Большой англо-русский словарь

Obligatory

adjective 1. binding in law or conscience 2. relating to or enforcing an obligation Example: a writ obligatory 3. mandatory, required Example: obligatory military service; also so commonplace as to be a convention, fashion, or cliché Example: the obligatory death scene in opera 4. obligate 1 • obligatorily adverb

Merriam-Webster's Collegiate Dictionary