The -c flag stands for "entry-comments." It allows you to add a one-line comment to each file as it is added to the archive.
Are you trying to get code from GitHub , or are you trying to write code that creates ZIP files ? Download c zip
A popular addition to zlib that adds the ability to create and extract .zip archives specifically. The -c flag stands for "entry-comments
How to download source in ZIP format from GitHub? [duplicate] Download c zip