FDISK /FPRMT [Windows 95B OSR2 + MS-DOS 7.10 and above ONLY]
FDISK /FPRMT bypasses the FDISK startup screen, but enables interactive FAT16/FAT32 support. This can be used to force FDISK to create FAT32 partitions smaller than 512 MB, normally not possible by default.

FDISK x /PRI:n (/PRIO:n) /EXT:n /LOG:n (/LOGO:n) [MS-DOS 6.00 and above ONLY]
FDISK x /PRI:n (or /PRIO:n) /EXT:n /LOG:n (or /LOGO:n) MUST be used together for proper operation. Meaning:

x = drive number: 1, 2, 3... etc. Drive 1 corresponds to the 1st hard disk installed (C), drive 2 to second hard disk (D)... etc.
/PRI:n = creates a primary partition of size n (in MegaBytes) and makes it bootable (active).
/PRIO:n = creates a primary partition of size n (in MegaBytes) and makes it bootable (active) while overriding FAT16/FAT32.
/EXT:n = creates an extended partition of size n (in MegaBytes) which holds logical partition(s).
/LOG:n = creates a logical drive in the extended partition of size n (in MegaBytes).
/LOGO:n = creates a logical drive in the extended partition of size n (in MegaBytes) while overriding FAT16/FAT32.
If using FAT16 maximum size allowed is 2,047 MB (2 GigaBytes).
If using FAT32 maximum size allowed is 2,047 GB (2 TeraBytes).
NOTES:
Maximum partition size MUST be equal to or smaller than existing free disk space.
/EXT:n and /LOG:n (or /LOGO:n) partition sizes MUST be identical.
Only one FDISK "LOG" is allowed per EACH logical drive! Therefore on computers with more than one logical drive you MUST run a separate FDISK x /LOG:n (or /LOGO:n) command for EACH installed drive.
ONLY IF using Windows 95B OSR 2.0 + MS-DOS 7.10 or newer: /PRI:n and /LOG:n default to FAT32 on partitions larger than 512 MB, or to FAT16 on partitions smaller than 512 MB. /PRIO:n and /LOGO:n default to FAT16 even on partitions larger than 512 MB, same as older MS-DOS 5.00/6.xx FDISK.
ONLY Windows 95B/95C OSR 2.x, 98, 98 SE(U), 2000, ME, XP and 2003 support FAT32.
Use /LOGO:n instead of /LOG:n and/or /PRIO:n instead of /PRI:n to ignore FAT information in case of disk access errors.
FDISK /MBR [MS-DOS 6.00 and above ONLY]
FDISK /MBR recreates the boot sector of the first (bootable) hard disk overwriting it with a fresh copy, by writing a new Master Boot Record (MBR) based on existent disk structure, without altering the partition table information.
Can be used to repair a damaged/corrupted MBR (i.e. by a virus).