Error in mounting FAT32 USB in Linux

Problem background:

When I mount an FAT32 USB drive in Linux, it will prompt an error something like below:

mount: you must specify the filesystem type.

I don't know what is that means, I usually will ignore it. Once I ignore this message, and continue with my task, I notice that some of the files with capital letters in it will gone after transfering from Linux to Windows through the USB drive. All the files/directory name are truncate into small capital font. I am so curious on this issue and I start to think of whether this is because of the different file format in between the two devices. Is this due to some missing bits during the write process to the device with different file format?

Solution:

mount -t vfat dev/sdb/ mnt/<mount_point>

This command will mount a FAT32 drive in Linux.