How to prevent MacOS from adding dot underscore files (._whatever.html )in zip archives?

Our organisation receives zip files from Mac users which contain a ._ file in addition to the file we expect. In the past this was due to resource fork and data fork encoding limitations on other file systems. So for example, when we expect a submission that looks like this: README.md src/mysite.html src/myscript.js we generally receive a zip that contains files such as: ._README.md README.md src/._mysite.html src/mysite.html src/._myscript.js src/myscript.js This makes it difficult for us to process these files automatically. What instructions should we give to our Mac users to suppress these files we can’t process or handle?