This documentation is not using the current rendering mechanism and is probably outdated. The extension maintainer should switch to the new system. Details on how to use the rendering mechanism can be found here.
In really old versions of TYPO3 CMS there were no tabs in the backend
forms. There were section which were indicated by the
separator in the TCA. Later on an option was introduced
('dividers2tabs') to transform the dividers into a tabbed screen.
Palettes were a feature to have extra (less important) fields in a group which could be made visible with the click on an icon.