What is being meant (i presume) is that even if you are a developer of those repos, do not edit them within the host repo. Work on them separately, as if you we

What is being meant (i presume) is that even if you are a developer of those repos, do not edit them within the host repo. Work on them separately, as if you were an independent developer, and then bump their revision as a submodule - the same you do with bumping a dependency version in your Makefile/package.json etc.