OBYC - Transaction GBB - General Modification - How to create?

Valuation Modification is nothing but valuation area.

General Modification is key that identifies type of goods movement. “General Modification” key is nothing but "Account modification" key in movement type.

The following general modifications are already assigned to appropriate movement types in standard SAP: For example:

AUF: for goods receipts for production orders with account assignment

BSA: for intial entries of stock balances

INV: for expense/revenue from inventory differences

VAX: for goods issues for sales orders without account assignment object

VAY: for goods issues for sales orders with account assignment object

VBO: for consumptiom from stock of material provided to vendor

VBR: for internal goods issues (e.g., for cost center)

VKA: for consumption for sales order without SD

VNG: for scapping/destruction

VQP: for sampling

ZOB: for goods receipts without purchase orders

ZOF: for goods receipts without production orders

Reference: http://www.jt77.com/material/management-17148.html

The last part of this guide:

If SAP standard “General modification” key is not useful for you, you can create your own movement type and assign your own “Account modification” (Must start with Z or Y).

<b>My question: How to do this? What menu path in SPRO or Tcode?</b>

Thanks in advance.