cmCpeBoardGroupMap is a read-only octet string where each octet is a numeric Group ID (such as 56 for cmCpeHDSLModemTable or 64 for cmCpeBoardTable) indicating which Copper Mountain database/MIB groups a given CPE supports. An administrator or management application reads this to know in advance which statistics and configuration tables it can safely query for that particular CPE, since not every CPE type populates every table. For example, before attempting to read cmCpeDataPortTable for a subscriber's CPE, the operator would first check whether cmCpeBoardGroupMap includes Group ID 130 to confirm that table applies to that unit.