WordPress at a glance
filter is not described

post_type_labels_(post_type) filter-hook . WP 3.5.0

Filters the labels of a specific post type.

The dynamic portion of the hook name, $post_type, refers to the post type slug.

Usage

add_filter( 'post_type_labels_(post_type)', 'filter_function_name_1396' );
function filter_function_name_1396( $labels ){
	// filter...

	return $labels;
}
$labels(object)
Object with labels for the post type as member variables.

Where the hook is called

get_post_type_labels()
post_type_labels_(post_type)
wp-includes/post.php 1562
$labels = apply_filters( "post_type_labels_{$post_type}", $labels );

Where the hook is used (in WP core)

Does not used.