A string of octets containing one bit per VLAN for VLANs
with values of 1024 through 2047 in the management domain
on this port.
If the VLAN represented by setting a bit to '1' in the
bitmap is a normal VLAN, it allows packets belonging to
this vlan on this Private VLAN trunk port.
If the bit corresponding to a VLAN is set to '1' and if
the corresponding VLAN is a normal VLAN, then the local
system is enabled to transmit and receive frames as
normal VLAN
If the bit corresponding to a VLAN is set to '0', and if
the corresponding VLAN is not configured as a secondary
VLAN, then the system is disabled from sending and receiving
frames on that VLAN via this Private VLAN trunk port.
This object is only instantiated on devices which support
the range of VlanIndexOrZero up to 4095.