How can I create discount on particular items only?

I want to have a discount on some items, not all the bill. I think if we can select the teams when we create the discount it will be so cool. 



As I know is not possible to create discount for particular items only, but you can apply a discount (eg. 5%) during sale for specific items, if you don't want to do it for all ticket. Here you can find more informations.