not obligatory; not required; optional (adjective)
Examples of word nonobligatory
We just obey because obeying someone like Jesus, who loves us, and only wants what is best for us, His children is like our nonobligatory gift to Him.
Traditionally, acts of beneficence are done from obligation, but they may also be performed from nonobligatory, optional moral ideals, which are standards that belong to a morality of meritorious aspiration in which individuals or institutions adopt goals that do not hold for everyone.
Use the other part of the pie to indicate how much of your circle is nonobligatory.
The two got the rest correct, including the nonobligatory "So help you God?"
I was the first to arrive for the nonobligatory lunch, and it was only reluctantly that he led me to the assigned table.