WordPress at a glance
filter is not described

loop_shop_post_in filter-hook . WC 1.0

Usage

add_filter( 'loop_shop_post_in', 'filter_function_name_6630' );
function filter_function_name_6630( $array ){
	// filter...

	return $array;
}
$array
-

Where the hook is called

WC_Query::product_query()
loop_shop_post_in
woocommerce/includes/class-wc-query.php 481
$q->set( 'post__in', array_unique( (array) apply_filters( 'loop_shop_post_in', array() ) ) );

Where in WP core the hook is used WooCommerce

Usage not found.