This is when a monastic holds a wrong view that goes against the teachings of the Buddha, and they have been remonstrated for holding that view up to three times by the sangha to encourage them to give up that view. If they do not give up that view, they are suspended by an act of the Sangha.
We see this in the Patimokkha in Pacittiya 68, Pacittiya 69
In Pacittiya 68 we see the monk Ariṭṭha has developed a wrong view about sensual pleasures, saying it is not a stumbling block to the holy life, despite having heard the teachings of the Buddha. The monks are obliged to remonstrate with him to give up that view:
“Do not, venerable one, speak thus … a veritable stumbling-block.” And a second time he should be told … And a third time he should be told … If he gives it up, 4.136 that is good. If he does not give it up, there is an offence of wrong-doing. If, having heard, they do not speak, there is an offence of wrong-doing. That monk, having been pulled to the midst of the Order, should be told: “Do not, venerable one, speak thus … a veritable stumbling-block.” And a second time he should be told … And a third time he should be told. … If he gives it up, that is good; if he does not give it up, there is an offence of wrong-doing.
So, he gets a pacittiya for not giving up the view and then he is to be taken before the Sangha to be censured and if he does not giveup that view, he should be suspended:
‘Honoured sirs, let the Order listen to me. A pernicious view has arisen to the monk so and so, like this: “In so far as I BD.3.26understand … no stumbling-block at all.” He does not give up that view. If it seems right to the Order, let the Order admonish the monk so and so that he may give up this view. This is the motion. Honoured sirs, let the Order listen to me: A pernicious view has arisen to the monk so and so … He does not give up this view. The Order admonishes the monk so and so that he may give up this view.
The following rule, Pacittiya 69 is called Ukkhittasambhoga where a monk has been suspended. It is an offence for another monk to eat with him, perform uposattha day activities with him , or even sleep under the same roof whilst that suspended monk holds on to a pernicious view and has not admitted his wrong view in front of the Sangha and been restored.
The rule also applies to monks who persistently refuse to acknowledge their offences.
There is more in the Khandakhas - but I have to go do duties now, will try to add later!