Final answer:
The U.S. government coding system that classifies a firm by the nature of its business operations is known as the Standard Industrial Classification code (SIC code).
Step-by-step explanation:
The U.S. government coding system that classifies a firm by the nature of its business operations is known as the Standard Industrial Classification code (SIC code)
The SIC code is a hierarchical system that assigns a unique code to each firm based on its primary economic activities. It was developed by the U.S. government to facilitate data collection, analysis, and reporting across industries.
For example, a company engaged in manufacturing electronic equipment may be assigned the SIC code 3651, while a company involved in retail trade may be assigned the SIC code 5331.