IPC 2013 : D21D 99/00 : Subject matter not provided for in other groups of this subclass.

IPC2013 > D > D21 > D21D > D21D 99/00[m] > Subject matter not provided for in other groups of this subclass.
D SECTION D — TEXTILES; PAPER.
D21 PAPER-MAKING; PRODUCTION OF CELLULOSE.
D21D TREATMENT OF THE MATERIALS BEFORE PASSING TO THE PAPER-MAKING MACHINE.
D21D 99/00 Subject matter not provided for in other groups of this subclass.