(i) A taxonomic class at the subgroup level of soil taxonomy having properties typical of the great group of which it is a member and that are characteristic of some class in a higher category (any order, suborder or great group) and indicates a transition to that kind of soil. (ii) A soil that is a member of one such subgroup. (iii)an expanding type 2:1 layer silicate which has islands of "gibbsite-like"cationic material in the interlayer spaces.