They prepend a '#' at the start of the ASIN, but then so does Calibre. It appears to be '#' followed by 10 characters followed by '^' followed by the book type. The 10 characters seem to start with B - but I'll just check if there are 10 and assume its ASIN as suggested. Thanks.
Now the tricky part is converting everyone's collections from the wrong code to the right code. Not too hard to do, but yet another check for legacy issues
