Why are spaces removed from the disk serial number?

I am investigating a bug report from a user where dmraid fails to 
recognize their array because one of the disks serial numbers does not 
appear to match the serial number recorded in the disk table slot for 
their isw raid ( which works fine in windows ).  It looks like dmraid 
reads the serial number from the disk with an inquiry command, then 
removes whitespace characters from it.  Why is this and could this be 
the cause of the problem?  Also, it appears that the disk serial number 
contains non ascii characters.  Is this normally allowed and how should 
they be interpreted?  UTF-8?

The full bug report can be found here:

https://bugs.launchpad.net/ubuntu/+source/dmraid/+bug/138130