We've seen some confusion about how to talk about private messages and their attributes. The message itself is not really private -- tools will still check if it exists. What's private is its interface: the value and any attributes.

Perhaps we could find a better wording to make this easier to understand? in #62 I originally proposed glossary messages; the feedback was that in the world of localization glossaries already have a defined meaning and it's better not to confuse people further.