Operational Control Language
Operational Control Language (OCL) is the control language of the IBM System/32, System/34 and System/36 minicomputer family. It is supported on IBM i's System/36 Environment for backwards compatibility purposes. It is similar to the older control languages JCL (System/370) and System/3, and unrelated to the later Control Language (System/38 and IBM AS/400), and REXX (AS/400). Overview. On the IBM S/32, S/34 and S/36, OCL statements are used to directly load user or system programs into memory, assign system resources to them, and transfer system control to them in a process called execution. The fact that a  program is stored on a computer's disk drive does not in itself cause the computer to process or execute the program. OCL statements can be entered manually from the keyboard, but are generally stored as a S/32, S/34, or S/36 procedure member. A procedure member is a freely editable member within a library, it is a source file. On the S/32, S/34, and S/36, procedures are not compiled, they are interpreted. Example. OCL statements usually begin with two slashes and at least one space character. Here's an example of a procedure stored on a System/36 as member PROC1 : // * 'PROC1 procedure is running' // IFF ACTIVE-'PROC2,PROC3' GOTO OKAY // PAUSE 'Cannot continue because other Payroll is running' // CANCEL Stops execution of this procedure // TAG OKAY // IFF DATAF1-PFILE1 IFF DATAF1-PFILE2 GOTO NODELT // * 'Caution, Pay Data Exists' Displays information on terminal // * 'Press 1 to continue and DELETE existing files' // IFF '1'=?1R? CANCEL A parameter is indicated by question marks surrounding a number // LOAD $DELET $DELET is used to delete files // RUN // IF DATAF1-PFILE1 SCRATCH UNIT-F1,LABEL-PFILE1 // IF DATAF1-PFILE2 SCRATCH UNIT-F1,LABEL-PFILE2 // END // TAG NODELT // LOAD PR101 PR101 could be an RPG or COBOL program  // FILE NAME-PAYMAST,DISP-SHR PAYMAST is the payroll master file // FILE NAME-PFILE1,DISP-NEW,RECORDS-100,EXTEND-100 // RUN // SWITCH 1XX0XXXX Causes flags U1 through U8 to be SETON (1), OFF (0), or left as previously set (X) // LOCAL OFFSET-1,DATA-'PROC1' Places PROC1 in the Local Data Area (LDA) // LOCAL OFFSET-101,DATA-'?USER?' Substitutes the operator's User ID // LOAD PR102 // FILE NAME-PAYMAST,DISP-SHR DISP-SHR means the file is shared, versus exclusive access // FILE NAME-PFILE,LABEL-PFILE1 NAME/LABEL is used when the RPG file name reference // RUN // RETURN Return to the calling procedure, otherwise end-of-job This procedure member  incorporates a variety of OCL statements, also procedure control expressions (PCE), resources, that is mostly files are allocated, and several job steps, that is programs are executed. Comments are represented by an asterisk in column 1, and otherwise free-format. Or can be placed after the logical end of a statement, if there is no indicator for statement continuation onto the next line, like a trailing comma. External links. IBM maintains manuals freely online and downloadable, including OCL 36.