How were dreams and visions seen in the context of Chinese Buddhism?

This question is prompted by reading the 23rd Minor Precept in the Brahma Net Sutra > After my passing, if a disciple should, with a wholesome mind, wish to > receive the Bodhisattva precepts, he may make a vow to do so before > the images of Buddhas and Bodhisattvas and practice repentance before > these images for seven days. If he then experiences a vision, he has > received the precepts. If he does not, he should continue doing so for > fourteen days, twenty-one days, or even a whole year, seeking to > witness an auspicious sign. After witnessing such a sign, he could, in > front of images of Buddhas and Bodhisattvas, formally receive the > precepts. At the modern moment, the normal advice regarding dreams and visions is to ignore them. So while I appreciate the concern, I'm not mainly trying to get advice about what to do about dreams and visions. What I see, in the above text is a positive perspective on dreams and visions, but the author assumes the reader knows what he's talking about when he says "vision"-- is this a reference to dreams, near-hallucinations during meditation, or "signs" like seeing something remarkable like crows listening to a dharma talk? Is this a reference to dream yoga that I hear about in Vajrayana?