CONCEPTS OF SCOPING:

a) With in the same scope, all identifiers must be unique.
b) Even when the datatypes are differing, variables and parameters cannot share the same name.

       Examlpe:
               DECLARE
                      V_FBoolean    BOOLEAN;
                      V_FBoolean    VARCHAR2(5):='SAMPLE';
               BEGIN
                      DBMS_OUTPUT.PUT_LINE('The Vlaue is:'||V_FBoolean);
                      V_FBoolean:=FALSE;
               END;

NAME RESOLUTION STANDARDS:

a) The Names of database columns take precedence over the names of local variables and formal parameters.
b) To avoid the ambiguity of name resolution, add a prefix to the names of the local variables and formal parameters, or a BLOCK LABEL can be used to qualify reference.