Defects found by the Coverity analysis are first filtered according to the settings here. If a defect matches all the filters, then it will be included in the list of "Coverity Defects" associated with the build, and in the defect count trend chart. Furthermore, if any defect matches the filters, and the "Fail the build if matching defects are found" box is checked, then the build will be marked as a failure.
Defects are filtered according to action, severity, component, checker, classification, impact and date found. If no value is checked for an attribute the filtering will match defects for all known values (the behavior with none selected is equivalent to all selected). If a date (yyyy-mm-dd) is specified, then only defects found on or after that date pass the filter. This is useful to establish a "base line" of existing defects that will be tolerated, whereas new defects will not be.