1
Animal
Specifies the medium being tested is an animal.
2
Human
Specifies the medium being tested is a human.
3
Sulphide
Specifies that the medium being tested is the sulphide component.
4
Aluminate
Specifies that the medium being tested is the aluminate component.
5
Silicate
Specifies that the medium being tested is the silicate component.
6
Oxide
Specifies that the medium being tested is the oxide component.
ZZZ
Mutually defined
Self explanatory.