The Descendant
This point refers to the cusp of the seventh house in all house systems, and is at the exact opposite point to the Ascendant, relating to others rather than the self. Any planets conjuncting the Descendant show an important requirement for companionship within relationships.
Ruling Planets
Ruling planets are those which rule the sign on any given house cusp, the most important being the Ruling Planet of the rising sign (Ascendant), which is considered the Ruling Planet of the whole birthchart. The house and sign in which the Ruling Planets are placed are extremely important areas. A person will sometimes look more like the sign in which the ruling planet of the Ascendant is placed than the ascending sign itself.
The Midheaven (MC)
This important point is the zenith of the birthchart and must fall between the eighth and 11th houses when using the Equal House System of division. It is more commonly found in the ninth or tenth houses, and with Placidus and other methods of division, it always forms the cusp of the tenth house. It is regarded as the high point of the chart wherever it falls - an area where great achievement or fulfillment can be recognized. Any planets forming a conjunction to the MC are extremely significant and should be viewed as "Angular."
Immum Coeli (IC)
This point is always in exact opposition (180 degrees) to the MC. It is therefore regarded as the nadir (lowest part) of the birthchart. It can fall anywhere between the second and fifth houses in the Equal House System, and usually signifies the quietest, most subjective point of the chart. Any planets forming a conjunction to the IC are important but are not considered Angular unless within an eight-degree orb of the cusp of the fourth house.
The Arabian Parts
There are many of these hypothetical, mathematically calculated points which refer to different categories such as the Part of Death, the Part of Marriage, and the Part of Children. The only one in common use today, however, is The Part of Fortune which is thought to be a beneficial point in which the sign and house occupied can bring good fortune through expression of the qualities represented.
The Nodes
Nodes are astronomical points within a planetary orbit as it crosses the ecliptic from South to N. (forming the North Node) and from North to South (forming the South Node). All the planets form nodes but only the Moon's are regarded as significant enough to be introduced into the birthchart. The Moon's Nodes are predominantly relevant within spiritual matters, relationships, and the arising of karma.