hmmm, well I found this at the border patrol site. It says they use the poly for suitability, so I'd guess it's something that doesn't have to be listed in the SF86 under the clearance section...I don’t know anything about other agencies hiring processes
"Suitability refers to an individual’s identifiable character traits and conduct that is sufficient to decide whether the individual’s employment or continued employment would or would not protect the integrity or promote the efficiency of the service. Suitability is distinguishable from a person’s ability to fulfill the qualification requirements of a job, as measured by experience, education, knowledge, and skills.
A security clearance is a determination that allows an employee access to classified information or systems when the employee has a “need to know.” A security clearance may be granted based on an administrative determination that an individual is eligible for access to classified information or systems based on the favorable security adjudication of a background investigation. Although all employees must meet the suitability requirements for employment, not all employees require a security clearance."