What is the difference between "AS" and "IS" in an Oracle stored procedure?

Answer

 Given a loose object type:

CREATE TYPE someRecordType AS OBJECT
(
   SomeCol VARCHAR2(12 BYTE)
);

You can create a loose Table type of this object type with either AS or IS

CREATE OR REPLACE TYPE someTableType
        IS {or AS} TABLE OF someRecordType;

However, if you create this same table type within a package, you must use IS:

CREATE OR REPLACE PACKAGE SomePackage IS
    TYPE packageTableType IS TABLE OF someRecordType;
END SomePackage;