For anyone else who is interested, I believe I did find what I was looking for:
"Certain aspects between charts may indicate psychological or spiritual work that needs to be done (or for those who believe in it, past life karma that has to be dealt with in this lifetime). These aspects appear in relationships that have a fated feeling to them. The relationship usually results in growth through the process of changing negative life patterns or beliefs. Karmic aspects do not indicate compatibility. In fact, the relationship could be very brief, only long enough to confront the repetition of a negative pattern and to make a decision about it. The idea of "soulmates" is very prevalent in astrology, and karmic aspects are often used as indicators of whether someone might be your soulmate. Whether or not soulmates exist or have karmic ties to us, having a lot of karmic aspects to another person does not make them your soulmate. It does not even make them necessarily likeable. But it does create a magnetic attraction (not necessarily a romantic one). Aspects that are considered karmic include:
Conjunctions (or possibly parallels) from one person's personal planet to the other's Saturn, Nodes or Chiron. Some astrologers only use the South Node as it indicates the past whereas the North Node indicates the future, however both nodes lend a fated feeling to the relationship. Trines and oppositions to Saturn or Chiron may be considered as well, but conjunctions are more significant.
Conjunctions (or parallels) between the Moon and Pluto or Neptune (some also consider Uranus)
Conjunctions or oppositions from one person's personal planet or Ascendant to the other's vertex
Conjunctions from personal planets to the IC "
(credit to astrologynotes.org/synastry)
Thank you also, Rohiniranjan for the thread reference - I am afraid that I am totally unfamiliar with many of the terms they are using, but still an interesting thread!
