Distributors please note: GS1 is an experimental package using expl3. Directory GS1 is a distribution of source an doc, that may be used by CTAN for tex-archive/macros/latex/contrib/GS1. GS1.tds.zip is a TDS distribution of GS1. You may use it for distributions like CTAN's /tex-archive/install/macros/latex/contrib/GS1.tds.zip.