ok im thinking about buying a male BCI for adrian, to breed with adrian. well my question is this.

http://alexhuereptiles.com/Boas/columbian.html

if you go there and look at the description for CAB-1M it says

Possible new line of Pastels. Female adult has produced these similarly appearing offspring for a few generations. This is a male, 465 grams - one year plus old. I would consider this male a B/B- grade animal.
what does the B/B- mean?