Why are the local variables listed in the argument?

b. Following is the procedure to retrieve number of persons, customer number and customer last name for the provided reservation ID as input: CREATE OR REPLACE PROCEDURE CUST_RESER_PROC ( |_RESERVATION_ID IN RESERVATION.RESERVATION_ID%TYPE, L_NUM_PERSONS OUT RESERVATION.NUM_PERSONS%TYPE, |_CUSTOMER_NUM OUT RESERVATION.CUSTOMER_NUM%TYPE, I_LAST_NAME OUT CUSTOMER.LAST_NAME%TYPE) AS BEGIN SELECT R.NUM_PERSONS, R.CUSTOMER_NUM, C.LAST_NAME INTO L_NUM_PERSONS, I_CUSTOMER_NUM, I_LAST_NAME FROM RESERVATION R, CUSTOMER C WHERE R.CUSTOMER_NUM = C.CUSTOMER_NUM AND R. R.RESERVATION_ID = |_ R.RESERVATION_ID; DBMS_OUTPUT.PUT_LINE(I_NUM_PERSONSTI'' ||L_CUSTOMER_NUMI"|| _LAST_NAME; EXCEPTION WHEN NO_DATA_FOUND THEN DBMS_OUTPUT.PUT_LINE('No records found'); END; /