WordPress at a glance
filter is not described

page_link filter-hook . WP 1.5.0

Filters the permalink for a page.

Usage

add_filter( 'page_link', 'filter_function_name_3712', 10, 3 );
function filter_function_name_3712( $link, $post_id, $sample ){
	// filter...

	return $link;
}
$link(string)
The page's permalink.
$post_id(int)
The ID of the page.
$sample(true/false)
Is it a sample permalink.

Where the hook is called

get_page_link()
wp-includes/link-template.php 331
return apply_filters( 'page_link', $link, $post->ID, $sample );

Where the hook is used (in WP core)

Does not used.