Time History Analysis Results - Member forces


Can someone give some clarification about the issue below?

In Section 5.31.4 of the STAAD.Pro Technical Reference Manual, in the Notes it says that for a Time History Analysis

"b Results are the individual maximums over the time period. Thus, derived quantities such as section forces and stresses, plate surface stresses and principal stresses should not be used".

Does this mean that the results for member forces in the postprocessing mode are onerous? 

Could you respond  ASAP to this query please?

Kind Regards,