General restrictions for ISMF customization include the following:

1. Before changing anything, you should make a backup copy of ISMF. Keep this unmodified version of the product for diagnostic purposes. IBM® support and maintenance is provided only for the unmodified version of ISMF.
2. Do not delete or rename any of the parts of ISMF. Deleting or renaming severely affects processing and can cause ISMF to fail.
3. ISMF is copyrighted. Under the IBM licensing agreement you may modify ISMF for your own use. You may not, however, modify it for commercial resale.