(under subclass 484) Devices or special constructions which form supports upon which the heaviest constituents of material form strata.
(1) Note. This subclass includes impermeable supports.
(2) Note. This subclass is to be distinguished from subclasses 506 and 507 in that in this subclass riffles either are not involved or are merely elements of a subcombination. Where the essential or special construction involved is that of the riffles, per se, the structure involved is classifiable in either subclass 506 or subclass 507.
