Application data element search order

When two or more input libraries are to be searched for an item, the search begins with the first library in a list and continues through the list until the item is found. For example, if the item searched for is of type "Panels" and a "LIBDEF with DATASET" service call is in effect, the input libraries (ISPPUSR, the LIBDEF defined library, and ISPPLIB) are searched consecutively in the order shown. The search stops when the item is found or when the last library has been searched.

The search of two or more output libraries proceeds in the same way, except that the first definition found is used as the repository for the output.

If no application-level libraries have been defined, the current set of allocated ISPF libraries is searched. If an application-level library is defined, it is searched before the allocated ISPF libraries.

Table 1 defines the search sequence for all item types.

Table 1. Search Sequence for Libraries
	No LIBDEF	LIBDEF with DATASET	LIBDEF with LIBRARY	LIBDEF with EXCLDATA	LIBDEF with EXCLLIBR
Panels	ISPPLIB	ISPPUSR LIBDEF ISPPLIB	LIBDEF ISPPLIB	Not valid	Not valid
Messages	ISPMLIB	ISPMUSR LIBDEF ISPMLIB	LIBDEF ISPMLIB	Not valid	Not valid
Table Input	ISPTLIB	ISPTUSR LIBDEF ISPTLIB	LIBDEF ISPTLIB	Not valid	Not valid
Skeleton	ISPSLIB	ISPSUSR LIBDEF ISPSLIB	LIBDEF ISPSLIB	Not valid	Not valid
Images	ISPILIB	ISPIUSR LIBDEF ISPILIB	LIBDEF ISPILIB	Not valid	Not valid
Linklib (See note following this table)	Job Pack Area ISPLLIB STEPLIB Link Pack Area LINKLIB	Job Pack Area ISPLUSR LIBDEF ISPLLIB STEPLIB Link Pack Area LINKLIB	Job Pack Area LIBDEF ISPLLIB STEPLIB Link Pack Area LINKLIB	Job Pack Area LIBDEF Link Pack Area LINKLIB	Job Pack Area LIBDEF Link Pack Area LINKLIB
Table Output	ISPTABL	ISPTABU LIBDEF	LIBDEF	Not valid	Not valid
File Tailoring Output	ISPFILE	ISPFILU LIBDEF	LIBDEF	Not valid	Not valid
Table Services (Input) with LIBRARY Parameter	Allocated Library	(Unchanged)	LIBDEF	Not valid	Not valid
Table Services (Output) with LIBRARY Parameter	Allocated Library	LIBDEF	(Unchanged)	Not valid	Not valid
File Tailoring Services (Output) with LIBRARY Parameter	Allocated Library	LIBDEF	(Unchanged)	Not valid	Not valid

Note:

If a program in Linklib is to be attached as a command processor (that is, by using the SELECT CMD parameter) and the command is not defined in the TSO command characteristics table (ISPTCM), the search sequence illustrated here does not apply. See z/OS V2R2 ISPF Planning and Customizing for information about customizing ISPTCM for the correct search order.
When using a SELECT with NEWAPPL, you must include PASSLIB to use the LIBDEFs you defined. For more details, see the description of the NEWAPPL parameter under SELECT—select a panel or function.
The image library with the associated ddname ISPILIB is not a required ISPF library. If you plan to use ISPF's image support in GUI mode, you must allocate the image input data set to ddname ISPILIB before using the images or before invoking the LIBDEF service with libtype ISPILIB.