The following code is very common in reporting programs:
FETCH      FIELDS(#PRODES) FROM_FILE(PROMST) WITH_KEY(#PRODNO)
IF_STATUS  IS_NOT(*OKAY)
CHANGE     FIELD(#PRODES) TO('''N/AVAILABLE''')
ENDIF
This effectively says, "if you can't find the product's description,  print it as N/AVAILABLE".
HOWEVER, the following code will achieve exactly the same result and save 2 lines of coding:
CHANGE     FIELD(#PRODES) TO('''N/AVAILABLE''')
FETCH      FIELDS(#PRODES) FROM_FILE(PROMST) WITH_KEY(#PRODNO)
If the FETCH fails to find any details, the product description field will remain unchanged.