The Information Center Facility contains several dialogs that are coded as CLISTs or REXX execs. You can improve the performance of the CLISTs/REXX execs the EXEC command finds at the system-level library (SYSPROC) and application-level library (defined using the TSO/E ALTLIB command), by using the virtual lookaside facility (VLF). To improve performance, define the IKJEXEC class name in the VLF PARMLIB member, COFVLFxx.