Email visibility is unclear and ill-documented.

[masklinn]

Since the addresses at /user/emails have individual visibility field and /user/email/visibility takes an email address as well as a visibility, it looks like visibility is a per-addess property.

However the property is nullable, and after experimenting it looks like it's only ever set for the primary address and really matches the profile-global "Keep my email addresses private" flag?

• is the inference correct
• if yes, could that be documented on the visibility property
• why does /user/email/visibility take an email address if that doesn't do anything useful and it always sets the visibility of the primary email address