A primary ledger is defined as a ledger where all your day-to-day transactions are performed and you would typically have a secondary ledger to reflect these same transactions in one of the following probable scenarios:
In a different Chart of Accounts
In a different Accounting Basis
In a different Currency (also called a Reporting Ledger)
This is an evolving functionality of Multiple Reporting Currencies (MRC) that was first introduced in the Release 11 to help with the transition to the Euro currency.
A secondary ledger is one that would, in most cases, replicate the transactions from the primary ledger so that these transactions can be adjusted and can be reported for specific financial or management purposes. The secondary ledger can also have a different accounting basis or a different Chart of Accounts. This functionality assists in maintaining the true value (at transaction time) of a single transaction in two (or more) scenarios.
There is no systematic upper...