TSSXTEND with WHOHAS option JCL is not found in the Top Secret documentation.
The WHOHAS option is a parameter in the MAINTIN DD Statement. The JCL is the same for all TSSXTEND jobs:
//YouJobID JOB (xxxxxx,xxxxx),SECFILE,
// CLASS=A,MSGCLASS=X,MSGLEVEL=(1,1),USER=msca
//*********************************************************************
//* . CAN ONLY BE RUN BY THE MSCA. *
//* *
//* . TAILOR THE JCL TO MEET YOUR SITE STANDARDS *
//* *
//* . THE OLDKEY AND NEWKEY FIELDS MUST BE 16-CHARACTER HEXIDECMIAL *
//* VALUE; THERE CAN BE NO EMBEDDED COMMAS OR SPACES. *
//* COMMENTS CAN NOT BE ADDED TO THESE FIELDS. *
//* *
//* !!!!!SAFEGUARD YOUR KEY FOREVER!!!!! *
//*********************************************************************
//EXTEND EXEC PGM=TSSXTEND
//MAINTOUT DD SYSOUT=A
//SECFOLD DD DISP=SHR,DSN=your.secfile.backup
//SECFNEW DD DISP=SHR,DSN=new.secfile
//* STEPLIB DD DSN=xxxxxxxxxxxxx,DISP=SHR, HR
//* VOL=SER=xxxxxx
//MAINTIN DD *
COPY SECURITY
OLDKEY=16digitsecuitykey
NEWKEY=16digitnewkey
WHOHAS
/*
The OLDKEY and NEWKEY can match to keep the same key.