These are a set of proposed properties meant to describe relative qualities of entities. They are meant to replace the use of has characteristic (P1552).
They all must be qualified with relative to (P2210) which states the highest class of the item the relationship applies to. For example, a train could be the longest vehicle, which would make it the longest train. We would just say it is the longest relative to (P2210)vehicle (Q42889), as that also implies that it is the longest train because the item is a train which is a vehicle, so it must be the longest train!