Before revision: 2018 Edition Though geothermal is not new in the 2018 edition, the title for the 2018 edition was revised to clarify that the code also pertains to geothermal energy systems.
After revision: energy2018 Edition Though geothermal is not new in the 2018 edition, the title for the 2018 edition was revised to clarify that the code also pertains to geothermal energy systems.