Motorcycles ofter use variable rate ("progressive") springs, while most
four-wheel vehicles use non-variable (linear) springs.  You can tell the
difference visually, since variable-rate springs have different distances
between the coils:  smaller at one end, larger at the other....

I thought this group was supposed to have a sense of humour-- a lot of
high-handedness on this issue.  It seems to me that most people have made
true claims, but the nomenclature is inconsistent, which leads unwarranted
browbeating.  Nobody is being "stupid" on this issue...  Chill out!