The amendment A1:2021 (published in 2021) is likely what you saw. Some systems concatenate numbers, turning "Part 1 – Amendment 1 - 2021" into a garbled "6193612021".
What changed in Amendment 1:2021?
A critical update involves the handling of switchgear. With the global push to reduce SF6 (Sulfur Hexafluoride) gas due to its high Global Warming Potential (GWP), the 2021 edition adapts design rules to accommodate GIS technologies that use alternative insulation gases (e.g., fluoroketones or compressed air). This includes updated pressure vessel safety guidelines and leak detection requirements. iec 6193612021 link
In many countries (EU via harmonized standards, Australia, Brazil, etc.), compliance with IEC 61936 is required by law for grid operators, industrial plant owners, and renewable energy farms to ensure personnel safety and grid reliability. The amendment A1:2021 (published in 2021) is likely