This identifies the board number that the accompanying per-board statistics in this row apply to, applicable to 6500 platforms. This serves the same indexing purpose as cdx6500NMNPIinventBoard did for inventory data, but here it ties statistical readings, memory, buffers, to a specific physical board on 6500-family nodes, letting an admin pinpoint which board's resources are under pressure in a multi-board chassis. For example, board number 2 showing unusually high memory usage compared to boards 1 and 3 would direct an admin's attention specifically to that board rather than treating the issue as node-wide.