Correlation names are generally used where two entities involved in the same request contain one or more identical field names. In such cases, the column names in the condition or sorting procedure have to be qualified, so as to indicate the entity to which they belong.
For example
As well as the CUSTOMERS table, there is an ORDER table, which contains the fields CORD_NUM, CCUST_NAME, CINVOICE_NUM.
/* Definition of a cursor associating orders with customers for customers in
/* post code area 38. Because the CCUST_NAME field is common to both entities, a
/* correlation name "A" is used.
CURSOR CURS1 CUST A, ORDER *COND(A.CCUST_NAME = CCUST_NAME AND A.CCUST_AREA = 38) *SORT(A.CCUST_TOWN)