The Galactic Empire: An Empire Reborn
Imperial Officers' Manual
Major Revision: 2.0 – 2008.10.31
An adaptation of the pre–Endor document and policies.
RIP
... A Master Sergeant's Rank Insignia...

Master Sergeant (MSG) is the highest rank any non-commissioned officer can achieve in the Imperial Army. These officers have served their units tirelessly both in and out of combat. Only superlative Staff Sergeants with a long and decorated record can reach the rank of Master Sergeant.

Since so many non-commissioned officers accept a commission and move up along that path, Master Sergeant is one of the most rare ranks in the Imperial Army. These officers are very familiar with how the Army operates and have proven themselves both loyal and capable in battle. As such, they are also charged with mentoring and guiding other non-commissioned officers and assisting their commanders when needed.

Finally, Master Sergeants act as Company First Sergeants, working closely with the Company Commander and Executive Officer. Their main responsibility is to ensure that all of the Enlisted and NCO members are prepared to go into battle at any moment.