How to trace a Package to it's source Registry?

When sharing a project (Julia scripts and respective Project.toml & Manifest.toml) with a co-worker, is there a way for this individual to know where the packages contained in the Project.toml come from? If some of the packages are coming from a private Registry, is this information recorded anywhere? At the moment I of course explain to my co-workers the Registry they need to add to their Julia setup, but I’m wondering if this is, or could/should be, recorded in the Project.toml or Manifest.toml files?