The south node is the point where the Moon crosses the ecliptic going south, and it lies exactly 180 degrees from the north node by construction. Whatever is true of the one is true of the other reversed, which is worth saying plainly because the two are often listed as though they were independently computed.
Both share the mean and true distinction. The mean south node regresses uniformly, a full circuit in about 18.6 years, roughly 3 minutes of arc a day, always retrograde. The true south node is the instantaneous crossing of the Moon's real orbit and oscillates around the mean by more than a degree on a period of about a fortnight, going briefly direct several times a year. An ephemeris that gives one gives the other by adding half a circle; there is no chart in which they disagree about the axis.
The 18.6 year cycle is long enough to be visible in other things. It is the period of the principal nutation of the Earth's axis, and it governs the extremes of the Moon's declination, which swing between about 18.3 and 28.6 degrees over the same interval. That second effect, the major and minor lunar standstill, is the one archaeoastronomers look for in prehistoric alignments, and it is the same physical cycle the astrological nodal return is counting.
Eclipses occur near this node as they do near the north, and in the same seasons.