Materials are materials that are manipulated in mass quantities. In general, material types just index vectors of values attached to other objects, such as unit supplies.
No more than 126 types of material may be defined.
Form: material-type
symbol properties...
This form defines a new type of material, named by symbol. Details are similar to those for unit types.
GlobalVariable: m*
This variable evaluates to a list of all material types, listed in the same order as they were defined.
GlobalVariable: non-material
This variable has a value that is never a material type.