例題
[C3170.cob] 000001 IDENTIFICATION DIVISION. 000002 PROGRAM-ID. C3170. 000003 ENVIRONMENT DIVISION. 000004 INPUT-OUTPUT SECTION. 000005 FILE-CONTROL. 000006 SELECT FILE-1 ASSIGN TO SYS001 000007 ORGANIZATION IS INDEXED 000008 ACCESS MODE IS SEQUENTIAL 000009 RECORD KEY IS KEY-REC. 000010 DATA DIVISION. 000011 FILE SECTION. 000012 FD FILE-1. 000013 01 REC-1. 000014 02 KEY-REC PIC XX. 000015 02 FILLER PIC X(78). 000016 WORKING-STORAGE SECTION. 000017 77 KEY-DATA PIC XX. 000018 PROCEDURE DIVISION. 000019 START FILE-1 KEY IS = KEY-DATA. 000020 STOP RUN.
C3170.cob 19: JMN3170I-S 索引ファイルを指定したSTART文のKEYに，RECORD KEY句またはALTERNATE RECORD KEY句で指定した項目またはそれに従属する項目以外は記述できません．
