This PmStatBitmap identifies which of the statistic(s) named in cienaCesPmAdjustmentTcaStats were actually responsible for establishing the current high watermark value, per its DESCRIPTION, and per PmTcaScheme this can be the same set of statistics being watched or only a subset of them. When Adjustment TCA is configured to watch more than one statistic on the same instance, this bitmap is what tells you which specific counter actually drove the watermark, rather than leaving you to guess which of several watched counters was the real culprit behind a TCA. For example, if AdjustmentTcaStats watches both Esl and Sesl on a DS3 port but this bitmap shows only Sesl set, you know the severely-errored-seconds counter, not the plain errored-seconds counter, is the one driving the current watermark.