We know about S2S contacts and we know what completes are, where you have both activated and chased a certain summit.
Here’s the next level. S2S completes. You have had S2S contacts between mountains X and Y in both directions. X-Y and Y-X.
A. the S2S completes were made with the same activator at the other end. This could result from a joint project between two or more activators.
B. The S2S Completes were made with different activators at the other end. This could result from unplanned happy coincidences…