This read-only Counter, with no default value, tracks the number of severely errored seconds received on all the links currently in the IMA group, defined by the documented formula that the sum of HEC errors across all links in a second must exceed HEC_SE_COUNT (defined as 10) times the number of links. An administrator uses this as a stricter threshold than the plain HEC errored-seconds counter, flagging seconds bad enough to meet this specific severity formula. For example, a group experiencing this counter incrementing, even while imaGrpRcvHecErrSecCount also increments, indicates the errors in those seconds were severe enough to cross the documented severity threshold rather than just being isolated single errors.