What characteristic best describes optional credits?

Optional credits in the context of Estidama and similar sustainability frameworks refer to performance evaluations that are not mandatory but can enhance a project's sustainability profile. Specifically, these credits allow project teams to pursue additional sustainability measures beyond the baseline requirements. It's a way to incentivize innovation and excellence in sustainable design and practices.

By choosing to pursue these optional credits, projects can gain further recognition and potentially achieve higher ratings. The voluntary nature signifies that these credits are not required for compliance with the basic standards but rather provide an opportunity for teams to go above and beyond in their sustainability efforts. This allows for flexibility and encourages creativity in how sustainability goals are achieved.

The other options do not properly capture the essence of optional credits. Mandatory requirements imply an enforced compliance, while restrictions by governmental policy and a linear application do not align with the flexible and innovative nature of optional credits.