How must boxes be identified in a dwelling unit?

In a dwelling unit, electrical boxes must be identified to indicate their function and connections. This requirement is crucial because it enhances safety and facilitates easier maintenance and troubleshooting for electricians and homeowners alike. Clear identification helps to understand the purpose of each box, such as whether they are for switches, outlets, or junctions. It also indicates how they are connected to the electrical system, which is vital for ensuring that circuits are not overloaded and that electrical work adheres to safety standards set forth by the National Electrical Code. Proper labeling can prevent accidental disconnection or confusion during repairs and assessments, thus promoting a safer electrical environment.