-@item -B
-@itemx --binary
-@opindex -B
-@opindex --binary
-@cindex binary and text I/O in cat
-On MS-DOS and MS-Windows only, read and write the files in binary mode.
-By default, @command{cat} on MS-DOS/MS-Windows uses binary mode only when
-standard output is redirected to a file or a pipe; this option overrides
-that. Binary file I/O is used so that the files retain their format
-(Unix text as opposed to DOS text and binary), because @command{cat} is
-frequently used as a file-copying program. Some options (see below)
-cause @command{cat} to read and write files in text mode because in those
-cases the original file contents aren't important (e.g., when lines are
-numbered by @command{cat}, or when line endings should be marked). This is
-so these options work as DOS/Windows users would expect; for example,
-DOS-style text files have their lines end with the CR-LF pair of
-characters, which won't be processed as an empty line by @option{-b} unless
-the file is read in text mode.
-