BAI2 Transaction Code 856 fails in Automatic Bank Statement Import - Format Profile

I'm trying to set up Automatic Bank Statement Import, and I encountered a problem that prevents us from importing a Bank of America BAI2 file:

The file could not be imported, because 856 is not one of the recognized bank transaction codes. 856 must be mapped to a bank data type in NetSuite. For details, contact your administrator. For a list of custom bank transaction codes, your administrator must contact your financial institution.

I thought maybe it's talking about the Custom Code mapping in the Format Profile, so I added one for 856 there.
Looking at a sample BAI2 file from Bank of America though, I noticed the lines starting with 16,856 each seem to be followed by a line that follows the pattern 88,CUR FR <ten-digit number here>.