In the booklet, an “oath” is best described as:

Detailed Explanation

The glossary treats an oath as more than a signature alone. In “Definitions and General Terms,” an oath is a verbal pledge given by the person taking it under an immediate sense of responsibility to God, and the booklet adds that the oath must be administered as required by law. For contrast, an affirmation is the equivalent used by persons who conscientiously decline taking an oath.