Verbal Codes are used when you do not want your employees/managers to see the numeric rating and just want them to see the verbal definition in the rating drop-down.

Employee and Manager's view of the review page:

However, the actual numeric calculation will always be shown to the HR/Admins along with the verbal definition when they open the review page from Org Dashboard.

HR/Admin's view of the review page:

Please note that the verbal code/definition for the overall score is derived by truncating the decimal part of the overall score. For example, even if a user has received 3.9 as the underlying overall score, the verbal code/definition will be shown for 3 as we truncate the decimal part to derive the verbal code/definition. Hence, it is highly recommended to use the Grading Scale option that lets you set your definition for a range of overall scores. This way the decimal part will not be truncated to draw the verbal definition.

Please read about the Grading scale option at https://engagedly.freshdesk.com/solution/articles/6000200137-what-is-manage-grades-option-in-the-performance-cycle-settings-