It's not. https://web.archive.org/web/20190324191654/https://www.ibm.com/support/knowledgecenter/zosbasics/com.ibm.zos.zsysprog/zsysprogc_initialization.htm htt

It's not. https://web.archive.org/web/20190324191654/https://www.ibm.com/support/knowledgecenter/zosbasics/com.ibm.zos.zsysprog/zsysprogc_initialization.htm https://web.archive.org/web/20190324191654/https://www.ibm.c... (archive.org link because ibm.com apparently isn't hosted on a mainframe.)