Where to put confidential data related to projects?

[info]

I need to store confidential data related to a project. It should be accessible (viewable/editable) by users with administrator access only.

[Nic Brough -Adaptavist-]

Somewhere else - there's no area restricted to administrators other than the actual admin functions.

You could have a separate admin-only project that stores stuff (a project of projects), or document things in Confluence - those are the two most popular options we see.