Below is a simplified reference based on IEC 60038 (Edition 7.0 or later):

: Common values include 120/208 V and 120/240 V .

standard defines the standard voltage values used for electrical supply systems and equipment design globally. It serves as the primary reference for ensuring compatibility between the power grid and electrical devices. IEC Webstore Core Voltage Classifications

Regardless of the "103" ambiguity, the heart of the standard is its voltage tables. Here are the critical values you need to memorize or reference.

: Standardizes industrial and distribution network voltages such as 11 kV and 33 kV .

Modern official PDFs from the IEC Webstore do not have fixed page numbers due to dynamic formatting, security restrictions, and watermarks. Therefore, any reference to “page 103” implies a specific scanned version, likely: