I spoke briefly about Right Livelihood earlier. The Buddha did talk about some livelihoods that he encouraged people to avoid. He encouraged people to avoid dealing in arms, weapons, dealing in poisons, and dealing in people - that is slavery - and also dealing in meat. Also being a soldier is being involved in killing of other beings. So there are a few livelihoods that the Buddha encouraged people not to do in if they want to develop themselves in this practice.
Other times, as I said, we have to use Right Intention and Compassion to look into our livelihood to see whether it is beneficial for society, whether it fulfills a beneficial side for society, and try to bring truthfulness and morality into our livelihood. Because as lay people, we have to provide for ourselves, for our family, and provide for the four necessities of life: food, clothing, shelter and medicines.