COBOL considerations: unlike PL/I, IBM COBOL does not normally provide for the manipulation of pointers (addresses). In order to allow COBOL programmers to access CICS control blocks and dynamic storage the designers resorted to what was essentially a hack. The COBOL "Linkage Section" was normally used for inter-program communication, such as parameter passing. The compiler generates a list of addresses, each called a "Base Locator for Linkage" (BLL) which were set on entry to the called program. The first BLL corresponds to the first item in the Linkage Section and so on. CICS allows the programmer to access and manipulate these by passing the address of the list as the first argument to the program. The BLLs can then be dynamically set, either by CICS or by the application to allow access to the corresponding structure in the Linkage Section.