There are several international standards and regulations related to electrical engineering that are important to be aware of in order to excel in the optional subject. These standards and regulations ensure safety, efficiency, and interoperability in the field of electrical engineering. Here are some of the key standards and regulations:

1. IEC (International Electrotechnical Commission) Standards:
- The IEC is a global organization that develops and publishes international standards for electrical engineering.
- These standards cover a wide range of topics such as electrical safety, electromagnetic compatibility, power systems, and measurement techniques.
- Familiarity with key IEC standards such as IEC 60038 (Standard Voltages), IEC 60092 (Electrical Installations in Ships), and IEC 60364 (Electrical Installations of Buildings) is essential.

2. IEEE (Institute of Electrical and Electronics Engineers) Standards:
- The IEEE is a leading professional organization that develops standards for electrical and electronic devices, systems, and services.
- IEEE standards cover areas such as power systems, communication protocols, electrical equipment testing, and renewable energy.
- Some important IEEE standards include IEEE 1584 (Arc-Flash Hazard Calculations), IEEE 802.11 (Wireless LAN), and IEEE 519 (Harmonic Limits for Power Systems).

3. NEC (National Electrical Code):
- The NEC is a standard for electrical installations in the United States and is widely adopted internationally.
- It provides requirements for safe electrical installations, covering areas such as wiring, grounding, and equipment installation.
- Being familiar with the latest edition of the NEC is important for electrical engineers working in the United States or dealing with American standards.

4. ISO (International Organization for Standardization) Standards:
- ISO develops international standards for various industries, including electrical engineering.
- ISO standards cover areas such as quality management systems, environmental management systems, and risk management.
- ISO 9001 (Quality Management Systems) and ISO 14001 (Environmental Management Systems) are examples of ISO standards relevant to electrical engineering.

In addition to these standards, it is important to be aware of specific regulations and codes that are applicable in your country or region. These may include building codes, electrical safety regulations, and industry-specific regulations.

Understanding and adhering to these international standards and regulations is essential for electrical engineers to ensure the safety, reliability, and efficiency of electrical systems and equipment.