BeagleBone CANBus Cape: why not marked bbb compatible?
Fragment of a discussion from Beagleboard talk:BeagleBone Capes
The can bus cape is marketed as "not compatible" with black current due to the fact there is no software support in the 3.8 kernel, see this table BeagleBone_Black_Capes. Note that the new can bus will have support and documentation. it's not recommended anyone purchase/use the existing revA can bus capes with beaglebone black.