Another situation where one might want to use a private discussion would be to point out in private some inappropriate behaviour to help guide rather than publicly shame an individual.

Any update about this issue?

It may be more great to separate the communication channels, like as private chats or dedicated collaboration tools, for sensitive or confidential discussions.

Try Chatzy.

If I understand, the root of the problem is that there doesn't seem to be a way to contact a Github user or group of users directly if they haven't made their e-mail addresses public.

Testing if my comment is public or not

Would love to see this!

We use GitHub for both our open- and closed-source development. It's often useful to be able to add a comment to an issue in a public repo that should not be shared beyond the maintainers. For example, we might add a note that a particular feature in an open-source product is needed for an as-yet-unannounced closed-source one.

We have other channels we can use for private conversation, of course, but associating such comments with the issues themselves makes them much easier to discover.

The workaround is issue linking. If we mention a public repo issue from a private repo one, GitHub helpfully creates a bi-directional link. This is fantastic, but we often want to provide more context (not just a link).

Similar to kring's comment, another currently unmet use case is to allow CI bots to publish commercially proprietary CI results (like competitive benchmark numbers) to PRs in public repositories.

+1 for this. We're currently using JIRA to manage progress of an issue internally because we cannot comment on the issue without these being publicly visible.

Echoing the use cases here plus another one - attaching a customer-provided screenshare or screenshot to a bug report, but not making it public to everyone on the internet.

I need to do this frequently.