WordPress at a glance
filter is not described

get_shortlink filter-hook . WP 3.0.0

Filters the shortlink for a post.

Usage

add_filter( 'get_shortlink', 'filter_function_name_5046', 10, 4 );
function filter_function_name_5046( $shortlink, $id, $context, $allow_slugs ){
	// filter...

	return $shortlink;
}
$shortlink(string)
Shortlink URL.
$id(int)
Post ID, or 0 for the current post.
$context(string)
The context for the link. One of 'post' or 'query',
$allow_slugs(true/false)
Whether to allow post slugs in the shortlink. Not used by default.

Where the hook is called

wp_get_shortlink()
wp-includes/link-template.php 3649
return apply_filters( 'get_shortlink', $shortlink, $id, $context, $allow_slugs );

Where the hook is used (in WP core)

Does not used.