Mark a thread as 'unread' after i read it

Hi there,

In the ED module, if there is an unread thread, its title will be bolded. And after i read it, the title became normal.

1. I'd like to know whether there is a functionality that shows 'Update' or something like that on a thread if there have been updates since the last time i looked at it?

2. Also, if there is a functionality that can mark a thread as 'unread' after i read it?


Thanks,
Song