WordPress at a glance
filter is not described

old_slug_redirect_post_id filter-hook . WP 4.9.3

Filters the old slug redirect post ID.

Usage

add_filter( 'old_slug_redirect_post_id', 'filter_function_name_4487' );
function filter_function_name_4487( $id ){
	// filter...

	return $id;
}
$id(int)
The redirect post ID.

Where the hook is called

wp_old_slug_redirect()
wp-includes/query.php 985
$id = apply_filters( 'old_slug_redirect_post_id', $id );

Where the hook is used (in WP core)

Does not used.