WP_MS_Sites_List_Table::column_default

		/**
		 * Fires for each registered custom column in the Sites list table.
		 *
		 * @since 3.1.0
		 *
		 * @param string $column_name The name of the column to display.
		 * @param int    $blog_id     The site ID.
		 */
		do_action( 'manage_sites_custom_column', $column_name, $blog['blog_id'] );
	}