Setting the book INACTIVE ON date

If the only way to disable a book is to set the book INACTIVE ON date, once the book is disabled what type of access do you have to the data?  Can you do inquiries? run reports?  We migrated the current data from one book in FA but we still have other active books in FA and we want to retain the book that we migrated the data from, in FA for historical data only.  I have found FAQ about disabling the book and a caution that once you set the book INATIVE ON date you can not remove that date, but I have not been able to find out