Chofetz Chaim Daily 11 Av 9:1 Asur to speak AVAK LH which is a negative inference eg. “who would think ploni would end up so good?”, “its better we dont talk about ploni” Praising ploni in presence of an enemy or excessive praise to any listener is also avak LH. 9:2 All praise is asur in public, except about universally accepted Tzaddik.
Chofetz Chaim Daily 12 Av 9:3 Asur to relate praise that may cause damage. Eg. Telling that ploni hosted you or lent you money, etc. This can cause ploni harm bc others will now demand the same. Asur to say something that can be mistaken for LH. 9:4 Asur to live among baalei LH. Asur to listen even if not intending to believe. One who finds himself in a group of LH speakers must protest even if you know they won’t listen.