Optatory 

When something is mandatory, but is not enforced, it becomes Optatory.

Stan missed the project meeting this morning, I guess he thought it was optatory.

Optatory by justananalyst May 8, 2018

optutory 

Optutory is an event or a meeting that is mandatory unless there is some emergency or important other thing that gets in the way.

Saturday's practice is optutory because we have the big game coming up, but I know prom is this weekend.

optutory by 877372 April 12, 2009