Graphical symbols for use on equipment. Index, survey and compilation of the single sheets; 4th Supplement

This document serves as the fourth supplement to a comprehensive collection of graphical symbols used on equipment. It provides an updated index and revised overview to ensure consistency within the broader body of standardized visual representations. The content focuses on organizing new symbols and refining existing categories without altering the core definitions established in the primary series. It acts as a reference tool for designers, manufacturers, and users seeking accurate visual indicators for safety, operation, and maintenance procedures. By incorporating specific additions and corrections, this publication maintains the integrity of the global framework for equipment labeling. It is designed to be integrated with the main index and summary sections to facilitate clear communication across international boundaries. The supplement reflects the collective expertise of the developing organization in standardizing technical graphics. It supports the continuous evolution of symbol sets to meet changing industrial and technological needs. The material is structured to allow easy retrieval and cross-referencing within the full set of graphical standards. This resource ensures that visual information remains unambiguous and universally understood by professionals in various technical fields.