You customize the Information Center Facility by changing the elements described in Information Center Facility structure. You can make those changes available by putting them in either the IBM-supplied data sets or in installation-supplied data sets. Be aware that if you place your changes in the IBM-supplied data sets, customizing future releases becomes more difficult. Customization then entails extracting your changes from the original data sets and adding them to the new data sets.

If you want your changed elements to reside in any data sets already allocated in the LOGON procedure or start-up CLIST/REXX exec, you do not have to change the concatenation in any installation LOGON procedures or start-up CLISTs/REXX execs. However, name these elements using a different naming convention to distinguish the installation-supplied members from IBM-supplied members. For information about the IBM-naming conventions for Information Center Facility elements, see Using the ICF naming conventions.

If you want your changes to reside in data sets that are not already in the data set concatenation in the installation LOGON procedure or start-up CLIST/REXX exec, you have to change the concatenation so users can access the changes you make. Again, you might want to use different member names, but if you decide not to, you must concatenate installation-supplied data sets ahead of the IBM-supplied data sets. If you use different names for the installation-supplied members, you must concatenate the installation-supplied data sets to the IBM-supplied data sets, but the order is unimportant.

When concatenating data sets, check that they all have the same record format.

IBM® distributes the CLIST and REXX library, ICQ.ICQCCLIB, with a RECFM of FB and an LRECL of 80. Only CLIST and REXX libraries with the same characteristics should be concatenated. If your production CLIST/REXX data set(s) has a RECFM of VB, run the CLIST ICQSMC00, a member of SYS1.SAMPLIB, against the CLIST/REXX libraries during installation to convert the libraries to a RECFM of VB.