[867] Origin at Sāvatthī. Now at that time the bhikkhus of the group of six taught the Dhamma to a person whose head was wrapped … "I will not teach the Dhamma to a person who is not sick whose head is wrapped" — thus should the training be undertaken.
**Wrapped head** means: it is wrapped so that the edge of the hair is not visible.
The Dhamma is not to be taught to a person who is not sick whose head is wrapped. Whoever, out of disrespect, teaches the Dhamma to a person who is not sick whose head is wrapped, incurs an offence of wrongdoing (dukkaṭa).
There is no offence: if it is unintentional; if he is unmindful; if he does not know; if [the listener] is sick; if he teaches after having him uncover the edge of the hair; in emergencies (āpadāsu); if he is insane; if he is the first offender.
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.