I suspect that what you heard, if it was specific to SSDs, refers to something different.
Any hard drive should be partitioned and formatted before first use. I suspect that what you were reading was referring to a Secure Erase, to ensure that the drive knows that all of its blocks are empty. Tom's does this to an SSD between passes of performance testing.
More than you ever wanted to know can be found here: http://csrc.nist.gov/publications/nistpubs/800-88/NISTSP800-88_rev1.pdf
or just download the Secure Erase utility from the University of California, San Diego (UCSD) CMRR site here: http://cmrr.ucsd.edu/people/Hughes/SecureErase.shtml