[Koha] how to create board , Class and Section (Additional attributes and identifiers)

hi how to create Additional attributes and identifiers Board---> class---> Section---> *S.No* *Board* *Class* *Section* *1* *CBSE* *1,2,3,......12* *A,b,c,d,---z* *2* *CIE* *1,2,3,......12* *A,b,c,d,---z* *3* *IB* *6,7,8,9,1O* *A,b,c,d,---z* -- Y.Yatheesh Babu +918247838231