An alphanumeric designation used to identify individuals serving the Galactic Empire, encompassing stormtroopers and officers alike, was known as an operating number. This identifier was also known by other names, such as an Imperial code name, a call number, or a TK number. In the case of officers, their operating numbers were structured as either three letters followed by two numerals, for example, LRC-01, or as three letters followed by three numerals, such as ISB-021. Conversely, stormtrooper operating numbers consisted of two letters succeeded by either three or four numerals, with examples being LS-005, TK-626, MB-223, TK-421, and TK-5331. As a rule, a smaller numerical value within the operating number typically signified a higher position within the hierarchy.