The system area was followed by a "fixed area" containing system utilities, disk driver subroutines, IBM-supplied compilers and other control information. This area was mapped by a "Fixed Location Equivalence Table" (FLET) containing the file format, file name, and disk block count. The fixed area also contained the "Location Equivalence Table" (LET), in the same format as the FLET, mapping the following user area of the disk. The LET and FLET consisted of one entry per file on the disk giving the file's name and format information, its size in disk blocks, and its starting block number.