| _tform_ | Trace data format (integer) |
| _tnrec_ | Number of records in multicomponent trace |
| _tdlen_ | Trace data length (bytes) |
| _tsint_ | Trace samling interval |
| _tnsam_ | Number of samples in the trace |
| lasttr | Last trace flag (=1 for last trace in ensemble; else 0) |
| seqno | Trace sequence number within a trace ensemble |
| timstrt | Trace time start |