References – Kd 18: The chapter on proper conduct 
“Can you expand on what is the korwat for how to treat teachers and how to treat guests?” Answered by Ajahn Ñāṇiko. [Protocols] [Respect for elders ] [Hospitality]
Vinaya: Khandhaka 18: Vattakkhandhaka and explanation in Buddhist Monastic Code Vol. 2, Chapter 13
Abhayagiri 25th Anniversary Retreat [2021], Session 16, Excerpt 3
“Is it possible for an arahant to have seemingly negative thoughts or speech while free from defilement? In the Udana, Venerable Pilindavaccha gets complained about for calling monks outcastes or lowlings.” Answered by Ajahn Pasanno. [Arahant] [Unskillful qualities] [Great disciples] [Harsh speech]
Sutta: Ud 3.6: Pilindavaccha.
Quote: “Purity or impurity—you have to know for yourself.” — Ajahn Chah. [Ajahn Chah]
Vinaya: Khandhaka 18.11.14 and Khandhaka 18.12.4: Students and teachers are mutually accountable. [Vinaya] [Mentoring]
Abhayagiri Monastic Retreat 2013, Session 1, Excerpt 2
“What is the role of admonishement? How do we admonish skillfully?” Answered by Ajahn Pasanno. [Admonishment/feedback ] [Monastic life] [Saṅgha] // [Right Intention] [Goodwill] [Mentoring] [Respect for elders]
Vinaya: Khandhaka 18.11.14, Khandhaka 18.12.8: Mutual admonishment between teacher and student.
Story: Ajahn Amaro waits a year before giving feedback. [Ajahn Amaro] [Patience]
Quote: “Don’t admonish somebody before the meal.” — Ajahn Chah. [Ajahn Chah]