well, the full text should be read:
SAP Accounting powered by SAP HANA is based on new General Ledger Accounting (FI-GL (New)) and uses functions such as ledgers to update a particular valuation, and the document splitting function. If you want to use SAP Accounting powered by SAP HANA, but were still using classic General Ledger Accounting until now, migrate the application data for General Ledger Accounting and the necessary settings for the new Customizing, for example ledgers and integration for Controlling.
However, none of the functions of new General Ledger Accounting, such as parallel ledgers and document splitting, are implemented..
The SAP Accounting powered by HANA uses Ledger concept, but still customer on classical GL can directly migrate to SAP Accounting by HANA.