Who says you cannot?
PP 5655-W32 IBM Enterprise COBOL for z/OS 5.1.1 MF0007 Date 05/26/2016 Time 09:28:42 Page 3
LineID PL SL ----+-*A-1-B--+----2----+----3----+----4----+----5----+----6----+----7-|--+----8 Map and Cross Reference
000001 000100 ID DIVISION.
000002 000200 PROGRAM-ID. MF0007.
000003 000300 ENVIRONMENT DIVISION.
000004 000400 CONFIGURATION SECTION.
000005 000500 DATA DIVISION.
000006 000600 WORKING-STORAGE SECTION.
000007 000700 01 WS-SOURCE. 0CL10
000008 000800 05 WS-SOURCE-DATA PIC X(10) VALUE '1234567890'. 000000000 10C
000009 000900 01 WS-TARGET REDEFINES WS-SOURCE. 0CL10
7
000010 001000 05 WS-TARGET-DATA PIC 9(10). 000000000 10C
000011 001100 PROCEDURE DIVISION.
000012 001200 0000-MAIN.
000013 001300 DISPLAY 'WS-TARGET-DATA >' WS-TARGET-DATA '<'. 10 10
000014 001400 STOP RUN.
PP 5655-W32 IBM Enterprise COBOL for z/OS 5.1.1 MF0007 Date 05/26/2016 Time 09:28:42 Page 4
Compiles just fine and displays
WS-TARGET-DATA >1234567890<
You cannot use OCCURS on an 01, but REDEFINES is perfectly fine.