ArrayTag
This class should be used for tags with value, that should be represented as a list of items.
Having a following class:
class Foo
{
    /**
     * @options black,white,green,"and so on"
     */
    public $value;
}
we obtain notations for value property:
$doc = (new ReflectionProperty('Foo', 'value'))->getDocComment();
$customTags = [new ArrayTag('options')];
$notations = getNotations($doc, $customTags);
var_export($notations);
The result will be
[
    'options' => ['black', 'white', 'green', 'and so on']
]