A501 Plant/Material
EBAN Purchase Requisition
EBKN Purchase Requisition Account Assignment
EKAB Release Documentation
EKBE History per Purchasing Document
EKET Scheduling Agreement Schedule Lines
EKKN Account Assignment in Purchasing Document
EKKO Purchasing Document Header
EKPO Purchasing Document Item
IKPF Header- Physical Inventory Document
ISEG Physical Inventory Document Items
LFA1 Vendor Master (General section)
LFB1 Vendor Master (Company Code)
NRIV Number range intervals
RESB Reservation/dependent requirements
T161T Texts for Purchasing Document Types
Other useful Link
Production Planning Certification Tutorial(SAP PP)