What additional ethics you find in Buddhism which are not found in other religions? What additional ethics you find in Buddhism which are not found in other religions?
Other religions mean Abrahamic religions, Hinduism, Taoism or any other religion you know.
I also like to know whether other religions have any ethics you do not find in Buddhism.
To start with concentrate on five, eight precepts compare them to other religions.
Divisive Speech.

This is definitely something unique to Buddhism (I think). Other religions talk about lying, but I don't remember any mentions of divisive speech. 


  Abandoning divisive speech he abstains from divisive speech. What he has heard here he does not tell there to break those people apart from these people here. What he has heard there he does not tell here to break these people apart from those people there. Thus reconciling those who have broken apart or cementing those who are united, he loves concord, delights in concord, enjoys concord, speaks things that create concord.


This comes from Buddha's special insight into the nature of dukkha. Dukkha comes from a conflict of mind, an unresolvable uninergated contradiction. Craving is one example of such contradiction, aversion is another, and conflict between people because of their incompatible views (about the world or about each other) is a third! 

So when you engage in divisive speech, you create and spread conflict between the sides, which will sooner or later bear the fruit of dukkha.

While the non-violence is taught by many religions, it is only (to my limited knowledge) in Buddhism is where the source of dukkha is understood so deeply that the role of divisive speech in creating dukkha is clearly recognized.

Harsh speech


  They give up harsh speech. They speak in a way that’s mellow, pleasing to the ear, lovely, going to the heart, polite, likable and agreeable to the people.