WordPress at a glance
filter is not described

wp_nav_menu_args filter-hook . WP 3.0.0

Filters the arguments used to display a navigation menu.

Usage

add_filter( 'wp_nav_menu_args', 'filter_function_name_5075' );
function filter_function_name_5075( $args ){
	// filter...

	return $args;
}
$args(array)
Array of wp_nav_menu() arguments.

Changelog

Since 3.0.0 Introduced.

Where the hook is called

wp_nav_menu()
wp_nav_menu_args
wp-includes/nav-menu-template.php 97
$args = apply_filters( 'wp_nav_menu_args', $args );

Where in WP core the hook is used WordPress

wp-includes/nav-menu-template.php 1324
add_filter( 'wp_nav_menu_args', array( $this, 'filter_wp_nav_menu_args' ), 1000 );