value in prtdiag BDF changed unexpectedly after applying recommended patch on M4000

Hello experts

My customer experience the value in BDF field was changed after applying recommended patch.
Would you tell me following three questions ?

- What is BDF ?
- Why is this changed ?
- What is the possible impact due to the change ?

What is done

   Kernel patch was upgraded from 142909-17 to 150400-30

What's the change (or issue?)

It seems just the value of "B" is changed, device path is persist between update and no service impact is
observed yet.

Following is the output of prtdiag, especially NIC area which is impacted.

142909-17, before upgrading kernel
-----------------------------------
00  PCIe  0       1, abcd, 108e     119,  0,  0  okay     8,    8  network-pciex108e,abcd         SUNW,pcie-qgc