The IDSS ( International Docking System Standard) is a docking standard that every Docking adapter should follow. According to its latest revision:
Vehicles using this interface may include light vehicles in the range of 5-8 tonnes, and medium vehicles in the range of 8-25 tonnes. These vehicles will dock to each other, to large space complexes in the range of 100-375 tonnes, and to large earth departure stages in the range of 33-170 tonnes
Upon reading more into the document I found out that it is mainly the soft capture system (SCS) and hard capture system (HCS) of the adapter that decide these mass ranges. But I'm still a bit confused as to how these systems affect the mass ranges. Also how can we increase these mass ranges?