Entering the "Change Primary Sort Header" command ("DP <parameter>") will sump the value of a parameters definition. Here are a few of examples:

dp axis

    axis=  t  x  y

dp fmt:segy

    fmt:segy=   typedef SEGY_CARD PREAMBLE;
   typedef SEGY_BINARY PREAMBLE2;
   typedef SEGY_TRACE SEQUENCE;

dp cmd_date

    cmd_date= Wed Jan  6 14:45:56 2010