For example, if you combine the primary DATASET filter and the secondary UNITADDR filter in the following way, you might get inaccurate results.

DATASET (INCLUDE (AAA.**)) UNITADDR (INCLUDE (0580))

The results of this combination would include data sets with the high-level qualifier of AAA, but of this group of data sets, only those on the device with the address 0580 would be included. This might cause you to artificially exclude some AAA data sets from the analysis, which would affect your report results.