i develop a plugin, which adds a section in manage submenu.
i found out that there is no way to indicate if that section is active or not (for the build-in sections, the active one doesn't appear as link)

so, i found a solution, which might be a good one :

@@@ html_api.php, line 987

• $t_event_menu_options = event_signal( 'EVENT_MENU_MANAGE');
• $t_event_menu_options = event_signal( 'EVENT_MENU_MANAGE', $p_page );

passing that argument to the plugin event handler seems to be sufficient.
in my plugin page i call print_manage_menu() with unique, plugin specific parameter which i expect in the event handler function for EVENT_MENU_MANAGE event.