the file control record (fcr) contains important information about btrieve database files. it holds the page size, the number of pages in current use, the number of keys that can index the file, the number of records in the file and other details. after version 6.0 two fcrs were used for redundancy. a 32-bit usage count field that exists in each fcr is used to determine which fcr was valid to use. each time an operation is done on a file the field is incremented. the fcr with the highest usage count becomes the valid fcr.