Words similar to optional

Example sentences for: optional

How can you use “optional” in a sentence? Here are some example sentences to help you improve your vocabulary:

and (2) a requirement that the current optional interim progress review between system integration and demonstration be a mandatory decision review requiring the program manager to verify that design is stable and that this be reported in the program's Defense Acquisition Executive Summary and Selected Acquisition Report.
Optional baseline for units in certain systems.
The casinos have no admission charge and formal dress is optional, though long pants for men are required.
According to the Times , schools such as New York City's nominally Catholic Fordham University--where Mass is optional and the chair of the theology department isn't even Catholic--are nonetheless concerned about the potential impact on their reputations.
Participation was optional and informed consent was obtained for all interactions.