Sylvia Boorstein:

Entry-level right speech is speech that doesn't add pain to any situation. This takes care of the obvious mistakes, like telling lies or purposely using speech hurtfully. High-level right speech maintains the balance of situations by not adding the destabilizing element of gossip. Gossiping is talking about someone not present. Except on rare occasions when one might need to convey a need on behalf another person, gossip is extra. Talking disparagingly about a third person is inviting the listener to share your grumbly mind space. Talking admiringly about a third person might cause your listener to feel unimportant. Why not choose to talk about current experience?