It is very common that people want to share document/variant/feedback comments for review with a limited set of colleagues before making them public. This would typically be people in their own organisation but not always. The reviewers should be able to included comments in the document that would not be later made public. Today this can only be done by converting to pdf/word/email but it would be much more convenient if it could be done within the tool itself.
Private user groups Merged
Sharing Variants - how to handle groups Merged