[Pharo-dev] Storing metadata along with .mcz packages

Hi there, I need to store a sort of a metadata along with the code in the .mcz. The goal is that if such a package is loaded by standard Pharo 2.0 (or 3.0) image, modified and then saved back as a new version, these metadata will be somehow preserved. Is that at all possible? If so, how? Best, Jan