Fe2S3 can be named using IUPAC nomenclature as either Iron(III) sulfide or Diiron trisulfide, depending on the version of the nomenclature being used. The discussion clarifies that the user is seeking guidance on naming compounds rather than writing their formulas. The key point is understanding how to modify the name of the second element in the compound, which involves changing its suffix to indicate its ionic state. The conversation emphasizes the importance of familiarizing oneself with IUPAC rules for proper compound naming. Overall, the thread provides insights into the correct nomenclature for Fe2S3 and resources for further understanding.