WordPress at a glance
filter is not described

wp_page_menu filter-hook . WP 2.7.0

Filters the HTML output of a page-based menu.

Usage

add_filter( 'wp_page_menu', 'filter_function_name_1335', 10, 2 );
function filter_function_name_1335( $menu, $args ){
	// filter...

	return $menu;
}
$menu(string)
The HTML output.
$args(array)
An array of arguments.

Where the hook is called

wp_page_menu()
wp-includes/post-template.php 1414
$menu = apply_filters( 'wp_page_menu', $menu, $args );

Where the hook is used (in WP core)

Does not used.