Not sure that anyone on this list gives a darn but just in case, here is a concrete example. I picked the COM DSECT (MODIFY and STOP interface for started tasks) -- it's small and people should be somewhat familiar with it. It's here: https://www.ibm.com/support/knowledgecenter/SSLTBW_2.3.0/com.ibm.zos.v2r3.ie ad100/COM.htm
Here is the CDSECT output (depending on options). Notice that it lost COMTOKEN -- thought only the flag bit was significant. #pragma pack(packed) #ifndef __iezcom__ #define __iezcom__ struct iezcom { void *comecbpt; /* - PTR TO ECB FOR STOP OR MODIFY COMMAND */ void *comcibpt; /* - PTR TO COMMAND INPUT BUFFER (CIB) */ int comtokhr : 1, /* - BIT = 1 INDICATES A TOKEN PRESENT */ : 31; }; #endif #pragma pack(reset) Charles