What feature did a customer use if they saved approximately 12,500 hours in document review time by identifying non-unique content?

The feature that enabled the customer to save approximately 12,500 hours in document review time by identifying non-unique content is email threading. Email threading analyzes email communications to group related messages together based on their conversational context. This allows legal teams or reviewers to understand the chronological flow of communication and eliminate duplicates and irrelevant threads, streamlining the review process significantly. By focusing on unique, relevant content rather than reviewing each email individually, the customer likely was able to make time-consuming document reviews more efficient.

In this scenario, email threading helps identify which emails are essential for the case, allowing teams to prioritize their time and focus on pertinent communications. The other options, while useful in certain contexts, do not directly pertain to the process of identifying and efficiently reviewing non-unique content in the way that email threading does.