How to Change the Value of $suckerfish

hi,
I need to add some more html tag to $suckerfish to control the display. And I make the change at phptemplate_menu_links in template.php. But looks like this doesn't take effective.

And what's more interesting is that I cannot find a place when value of $suckerfish is defined and assigned. It should be somewhere as it's not a predefined Drupal variance for tempate.

Can you help me answer above question?

Thanks,
Ray,