Which modification type includes changes authorized by clauses other than a changes clause?

The correct choice is that the modification type which includes changes authorized by clauses other than a changes clause is referred to as unilateral modifications.

Unilateral modifications are initiated unilaterally by the contracting officer and can encompass a variety of changes that arise from different clauses in the contract. These changes could include adjustments for government-directed changes or other regulatory adjustments that do not require the contractor's consent. Unilateral modifications are commonly used when the government needs to make changes that are clearly defined and do not require negotiation with the contractor, thereby allowing for efficient management of the contract.

This type of modification is distinguished from others, such as bilateral modifications, which require agreement from both parties and are commonly used for mutual changes. Similarly, supplemental and administrative modifications do not typically encapsulate changes from clauses other than the changes clause, as supplemental modifications are often used to add provisions or clarify contract language, while administrative modifications are used for minor, non-substantive changes.

Understanding the nuances of unilateral modifications is key for managing contracts effectively, particularly in ensuring compliance with regulatory guidelines while minimizing disruptions.