Understanding the fields in a CTE

The following fields are common in every CTE:

Length (CTELENP)
A 2-byte field containing the length of the entire CTE, including this length field (CTELENP) and the trailing length field (CTELENE). The maximum CTE size is 64KB. This field is at the beginning of the CTE.
Offset (CTEOFF)
A 2-byte field containing the offset of the variable data within the CTE.
Entry Identifier (CTEFMTID)
A 4-byte field containing a user-defined identifier. This indicates the type of event traced by the entry, and is also specified on the ITTFMTB macro EVENTDATA keyword in the corresponding format table entry for formatting purposes.
Time (CTETIME)
An 8-byte field containing the time stamp. IBM® recommends that you create the time stamp using the STCK instruction, which produces Coordinated universal time (UTC). During formatting, the user of IPCS can request that the time stamps be formatted in local time only if you created the time stamps in UTC.
Variable Data (CTEVDATA)
A variable-length field to contain application-unique data in any format. The maximum length of this field is 60KB. See Organizing variable data in CTEs for suggestions on how to organize this field.
Trailing Length (CTELENE)
A 2-byte field containing the length of the entire CTE, consistent with the value in CTELENP. This field is at the end of the CTE.

For complete field names and lengths, offsets, and descriptions of the fields mapped by the ITTCTE mapping macro, see ITTCTE in z/OS MVS Data Areas in the z/OS Internet library.