There are two types of encounters, the first type is where the abductee is forcebly taken against their will, while the second form of contact involves willful agreement to be abducted by an abductee.
There are two types of CE4 encounters, the first type involving forceble abduction by an extraterrestrial intelligence by an unwilling abductee. The second type of CE4 contact involves willful agreement to be abducted by an abductee.