Version 6.3.3 from the Library of Congress - https://www.loc.gov/preservation/digital/formats/digformatspecs/APPNOTE%2820120901%29_Version_6.3.3.txt https://www

Version 6.3.3 from the Library of Congress - https://www.loc.gov/preservation/digital/formats/digformatspecs/APPNOTE%2820120901%29_Version_6.3.3.txt https://www.loc.gov/preservation/digital/formats/digformatsp... Writeup on zip file Appnotes: https://entropymine.wordpress.com/2019/08/22/survey-of-zip-appnote-documents/ https://entropymine.wordpress.com/2019/08/22/survey-of-zip-a... Actual PKWare AppNotes: https://support.pkware.com/display/PKZIP/Application+Note+Archives https://support.pkware.com/display/PKZIP/Application+Note+Ar... Section 4.4.5 is "compression method"