Some common reasons include: 1  a serious accident â such as a road accident, a severe head injury, a serious fall or severe burns. 2  a serious short-term condition â such as a heart attack or a stroke. 3  a serious infection â such as sepsis (blood poisoning) or severe pneumonia.
The definition of unnecessary is not needed. An example of something unnecessary is a bowl of sugar for cooking meatballs.
In the US, attending school through the twelfth grade, driving on the right side of the road, and obtaining a social security number are all mandatory. The phrase mandatory requirement is redundant. A mandatory action is something that is required, obligatory, or compulsory. Like letting your Great Aunt Edna pinch your cheeks or passing gym to get your diploma. Mandatory is often used in opposition to optional.