SECLABEL is only used if RACF® is installed and security label checking is active. Upon initial invocation of IKJEFLN1, this parameter contains either the value from the previous TSO/E session or the value the user specified on the LOGON command. Upon subsequent entry to IKJEFLN1, this parameter contains the RACF security label entered on the logon panel. If your installation uses RACF, you can use this parameter to supply a different RACF security label to the logon panel. SECLABEL is the RACF security label. The maximum length of the SECLABEL is 8 bytes.