Judy Hirst explains Inventory Reconcile to GL in Dynamics GP 2013.
Dynamics GP 2013 – Inventory Reconcile to GL – Etelligent Solutions
General Ledger & FinancialsSales, Purchasing & InventoryGP 2013
Archived post from 2013. Dynamics GP and the links it points to have changed since; check current documentation before relying on version-specific steps.