The aiguillette is a decorative cord or braid worn on military uniforms that serves several purposes:

1. It signifies the wearer's role as an aide-de-camp or adjutant to a senior officer, head of state, or other high-ranking official.
2. It denotes ceremonial status, particularly for officers serving in specific staff positions or honorary roles.
3. It indicates the wearer's branch of service or unit in some military organizations.

The aiguillette originated in practical battlefield use - it was a cord used by cavalry to tie up horses or carry items like cleaning picks for firearms. Over time, it evolved into a purely decorative and symbolic element of military dress uniforms.

Today, aiguillettes are typically worn on the right or left shoulder (depending on the country's military tradition) and consist of braided cords ending in metal tips or "aiglets." Different colors, patterns, and wearing positions can indicate specific ranks or roles within a military organization.

https://www.glendale.com/search.php?search_query=Aiguillettes%3A+US+Army+Bandsman