[TYPO3] Problem understanding $TCA['tt_content']['types']

[micho edo]

Dmitry Dulepov [typo3] schrieb:
> Hi!
> 
> micho edo wrote:
>> I don´t understand the meaning of the elements of 
>> $TCA['tt_content']['types']
>>
>> In some examples, definitions are inserted under the key ['list']
>> for example $TCA['tt_content']['types']['list'].xxxxxx
>>
>> What´s defined in the layer direct after $TCA['tt_content']['types'] 
>> (here ['list'])
>>
>> Where is this key 'list' used
> 
> Use documentation! :)
> 
> http://typo3.org/documentation/document-library/core-documentation/doc_core_api/4.1.0/view/4/2/#id3664615
> 

Thanks.
maybe you can help me another time.
where cna I define which type a frontendplugin shall use.

The kickstarter generated:
$TCA['tt_content']['types']['list']['subtypes_excludelist'][$_EXTKEY.'_pi1']= 
  'layout,select_key';
t3lib_extMgm::addPiFlexFormValue($_EXTKEY.'_pi1', 
'FILE:EXT:'.$_EXTKEY.'/flexform_ds.xml');
t3lib_extMgm::addPlugin(array('LLL:EXT:bbc_ruby/locallang_db.xml:tt_content.list_type_pi1', 
$_EXTKEY.'_pi1'),'list_type');

I think the type here is: 'list'.
The addPlugin function defined as type: 'list_type'

If a want to add an new typ test77, is this code correct?

$TCA['tt_content']['types']['test77']['subtypes_excludelist'][$_EXTKEY.'_pi1']= 
  'layout,select_key';
t3lib_extMgm::addPlugin(array('LLL:EXT:bbc_ruby/locallang_db.xml:tt_content.list_type_pi1', 
$_EXTKEY.'_pi1'),'test77_type');

thanks!