The Buddha shares in brief the four kinds of verbal good conduct - 1) truthful speech, 2) non-divisive speech, 3) gentle speech, and 4) wise counsel.

Sucarita sutta - Good Conduct

"Bhikkhus, there are these four kinds of verbal good conduct. What four?

1 Truthful speech,

2 non-divisive speech,

3 gentle speech,

4 wise counsel.

These are the four kinds of verbal good conduct."