Had you forgotten that such a feature, in a different form, has existed since PGV days?
If there are notes present, the tab is displayed as a normal tab.
If there are no notes, two options exist:
- If the user can add/edit data, the notes tab is shown, but rendered semi-opaque. (different old themes do this slightly different. Customisations could change this in many ways)
- If the user can not add/edit data, or is a non-registered visitor the tab is not displayed.
The same applies to most tabs.
I haven’t changed it for kiwitrees-nova. Is there a reason it should change, other than the theme you use perhaps needs ‘improving’ slightly for your needs?