TYPO3 Core

Since the introduction of itemGroups in TYPO3 v10, the index for descriptions has shifted from 3 to 4.
Before that, the index 4 was used for the authMode option, to explicitly deny or allow single items.
Now the index 4 is used for two completely separate purposes.

Example:

        'select_checkbox_1' => [
            'exclude' => 1,
            'label' => 'select_checkbox_1 description',
            'description' => 'field description',
            'config' => [
                'type' => 'select',
                'renderType' => 'selectCheckBox',
                'authMode' => 'individual',
                'items' => [
                    ['foo 1', 1, '', '', 'EXPL_ALLOW'],
                    ['foo 2', 2, '', '', 'Description2'],
                    ['foo 3', 3, '', '', 'Description3'],
                ],
            ],
        ],

When the first item is visble for the editor, the description will be "EXPL_ALLOW", which is not desireable. There is no way to define another description either, because the index is already occupied.