TYPO3 Core

TYPO3 allows us to specify an icon that is displayed in front of options in BE selectors (this is currently only supported by Mozilla based browsers AFAIK).
Additionally it's possible to group option tags by inserting a "---div---" item, resulting in a <optgroup> tag.
Unfortunately the styling of the optgroups is currently broken, which makes them unusable in Mozilla (See attached snapshots).

Put following lines around the registration of a plugin to your ext_tables:

$TCA['tt_content']['columns']['list_type']['config']['items'][] = array('group header', '--div--', t3lib_extMgm::extRelPath($_EXTKEY) . 'ext_icon.gif');

// t3lib_extMgm::addPlugin(...);

$TCA['tt_content']['columns']['list_type']['config']['items'][] = array('', '--div--');

A proper support for optgroups would be especially useful in the plugin list which gets confusing with a lot of entries.

Background: we might add a new method to Extbase allowing you to register multiple plugins at once semantically grouping them together
(issue imported from #M16465)