Type: Internal (3.1 and later)
Purpose: Used in the CONFIG.SYS file to specify the number of file-control blocks (FCBs) for file sharing.
You should only include an FCBs in your CONFIG.SYS if the program you are using requires it. Most newer programs do not use FCBs. For more information on the FCBS command, refer to Chapter 6, Tips for Advanced Users. Option number – Specifies the maximum number (1 to 255) of open FCBs that a program can use. The default is 4.