Add custom fields to drupal navigation menu without breaking the version

Question

Is it possible to add custom fields to drupal navigation menu (besides title and description)?
I want to keep the version without breaking it.

Answer 1

There's a module for that. Menu attributes: http://drupal.org/project/menu_attributes .This module specify some additional attributes for menu items

If you need a more complex solution, you can reuse the code of menu attributes and write your custom fields.

Answer 2

What kind of fields are we talking about? If you just want to control the aesthetics of your menu, by adding, let's say, icons to some menu entries, you could write your own theme function for the menu. There is a nice writeup here: http://programmingbulls.com/complete-drupal-6-menu-theming or you could just check the docs: http://api.drupal.org/api/search/6/theme_menu