General Guidance

Because ISMF was written using the procedures described in ISPF Dialog Management Services it can be modified using the same techniques. DFSMSdss/ISMF, DFSMShsm/ISMF, ICKDSF/ISMF, and DFSORT/ISMF can also be modified with these techniques. IBM® provides replaceable modules that allow you to extend the function of ISMF.

Restrictions to Customizing

Before you change ISMF, you must be aware of the following three restrictions:

Make a backup copy of ISMF before you make any changes. Keep this unmodified version of the product for diagnostic purposes. IBM support and maintenance are provided for only the unmodified version of ISMF.
Do not delete or rename any of the parts of ISMF. Deleting or renaming a part could severely impact processing, or cause ISMF to fail.
ISMF is copyrighted. Under the IBM licensing agreement you may modify ISMF for your own use. You may not modify it for commercial resale.

Other restrictions apply to the individual parts. These are presented with the detailed descriptions of how to modify each part throughout the remainder of this section.

The Parts of ISMF That You Can Customize

ISMF allows you to customize the following parts for all ISMF applications:

Panels
Messages
Job skeletons
Command tables
CLISTs

The parts are shipped in individual libraries. The changes you can make to each library are discussed in The Panel Library.

The Panel Library

ISMF allows you to make the following changes to the panel library:

Change the initial priming values that ISMF ships
Change the default values for data entry panels
Provide additional restrictions to values entered for certain fields on panels
Remove fields from functional panels
Change highlighting and color
Change the format of the panel
Modify existing functional panel text and help text
Add new fields to panels
Add new panels

The Message Library

In the message library you can modify existing messages and add new messages.

The Skeleton Library

In the skeleton library you can modify the job skeletons for ISMF commands and line operators.

The Table Library

In the table library you can modify the ISPF command tables.

The Load Library

In the load library you can modify the ISMF command and line operator tables. The tables are contained in nonexecutable CSECTs in the load library.

The CLIST Library

In the CLIST library you can modify the options on the CLIST CONTROL statement.

Finding the Libraries You Want to Customize

If you are currently running ISMF, you can use the procedures described in this section to find the ISMF libraries you want to customize. If you are not running ISMF, and you need information about linking to the correct libraries, these books will help you:

z/OS DFSORT Installation and Customization
ICKDSF System Control Programming Specifications

Once you are linked to ISMF, the method you use to find the ISMF libraries depends on the library you want to modify.

Panel, Message, Skeleton, and Table Libraries

To find the correct libraries for panels, messages, skeletons, and tables, use the TSO LISTALC STATUS command to determine the data set name associated with the DDNAME for the library. Table 1 lists the DDNAMEs that ISMF uses:

Table 1. DDNAMEs for the Panel, Message, Skeleton, and Table Libraries
Library	DDNAME
Panel	ISPPLIB
Message	ISPMLIB
Skeleton	ISPSLIB
Table	ISPTLIB¹ ISPTABL²
Notes: Input table library Output table library

Load and CLIST Library

The placement of the load library and the CLIST library is determined by the way ISMF is installed. The CLIST library DDNAME is SYSPROC. The load library may be given a DDNAME ISPLLIB or STEPLIB, or it may be made a part of the link pack area or the system link library.

Restriction: You cannot allocate the load library using the ISPF/PDF LIBDEF service because ISMF issues the LOAD macro.

Table 2 lists the DDNAME for the CLIST library and location or DDNAME for the load library.

Table 2. DDNAMEs or Locations for the Load and CLIST Libraries
Library	Location/DDNAME
Load	ISPLLIB or STEPLIB or System link library or Link pack area
CLIST	SYSPROC

Making and Testing Changes

The best way to make and test changes in any of the ISMF libraries is to copy the member you want to modify from the ISMF library into a personal library. Add your library to the beginning of the existing concatenation that you or your installation uses. This ensures that you can safely make changes without impacting the other libraries in the concatenation.

Once you've tested the changes, you can then change the concatenation to make the modified part available to a larger group of people, your department for example. If you want the change to be used by the entire installation, you can copy the member from your personal library back into the ISMF library.

For members of the panel, message, skeleton, table, and CLIST libraries you can note the changes in the comment section at the beginning of the modified member. Remember to keep an unmodified copy for service and maintenance.

Exception: The load library is an exception to the above guidelines. The methods you can use to modify the static text and ISMF tables in the load library are discussed in Customizing the ISMF Command and Line Operator Tables.