Source

File: wp-admin/includes/class-wp-links-list-table.php

public function get_columns() {
		return array(
			'cb'         => '<input type="checkbox" />',
			'name'       => _x( 'Name', 'link name' ),
			'url'        => __( 'URL' ),
			'categories' => __( 'Categories' ),
			'rel'        => __( 'Relationship' ),
			'visible'    => __( 'Visible' ),
			'rating'     => __( 'Rating' ),
		);
	}