What is a prohibited styling for sideburns?

The prohibition against styling sideburns "with flair" stems from the Army's emphasis on maintaining a professional and uniform appearance. The Army Regulation on grooming standards specifically defines acceptable styles for sideburns, which include guidelines on length, shape, and how they integrate with the overall haircut.

Sideburns styled with flair typically involve exaggerated or decorative features that diverge from a simple, clean look. This creative styling undermines the uniformity and discipline that military appearance standards aim to uphold. In contrast, rounded ends and soft tapered edges reflect traditional, acceptable forms that comply with Army grooming policies, highlighting a neat and professional demeanor. Hence, the choice of styling sideburns "with flair" is the correct answer as it directly conflicts with those established standards.