WordPress at a glance
filter is not described

get_post_galleries filter-hook . WP 3.6.0

Filters the list of all found galleries in the given post.

Usage

add_filter( 'get_post_galleries', 'filter_function_name_2788', 10, 2 );
function filter_function_name_2788( $galleries, $post ){
	// filter...

	return $galleries;
}
$galleries(array)
Associative array of all found post galleries.
$post(WP_Post)
Post object.

Where the hook is called

get_post_galleries()
wp-includes/media.php 3817
return apply_filters( 'get_post_galleries', $galleries, $post );

Where the hook is used (in WP core)

Does not used.