wipefs

wipefs can remove signatures, labels, and RAID info from block devices. In some cases, gdisk will recommend using it.

By default, will show them:

/sbin/wipefs /dev/sdc

From a USB drive imaged with an Ubuntu .img file:

offset               type
----------------------------------------------------------------
0x1fe                dos   [partition table]

0x8001               iso9660   [filesystem]
                     LABEL: Ubuntu-Server 16.04.2 LTS i386
                     UUID:  2017-02-15-20-43-45-00