Resources:

"Anatomy of a MDL Mol File" Slideshow presentation: https://chem.libretexts.org/Courses/University_of_Arkansas_Little_Rock/ChemInformatics_(2017)%3A_Chem_4399_5399/2.2%3A_Chemical_Representations_on_Computer%3A_Part_II/2.2.2%3A_Anatomy_of_a_MOL_file

"What is the correct format for compounds in SDF or MOL files?" https://www.nonlinear.com/progenesis/sdf-studio/v0.9/faq/sdf-file-format-guidance.aspx

Technical specification of Elsevier MDL’s CTfiles and V2000 connection tables: http://c4.cabrillo.edu/404/ctfile.pdf

Overview of Chemical File Formats: https://en.wikipedia.org/wiki/Chemical_file_format#Other_common_formats

Details on Chemical File Tables (including MDL Mol): https://en.wikipedia.org/wiki/Chemical_table_file