Generally, it is defined as favoritism shown to a relative.
Prohibition: Generally, an employee may not appoint, employ, promote, or advance a relative in or to a position within the Department (not just your bureau) over which the employee exercises jurisdiction or control over the relative. It is also a violation of both the Merit System Principles and a Prohibited Personnel Practice – subject to investigation by the U.S. Office of Special Counsel.
"Relative" means an individual who is related to an employee as a father, mother, son, daughter, brother, sister, uncle, aunt, first cousin, nephew, niece, husband, wife, father-in-law, mother-in-law, son-in-law, daughter-in-law, brother-in-law, sister-in-law, stepfather, stepmother, stepson, stepdaughter, stepbrother, stepsister, half brother, or half sister.