The registerColumnType method of org.hibernate.dialect.Oracle10gDialect only seems to allow for one "name" per JDBC type code. In a legacy database implementation that we are trying to work with we have:
{{TYPE "PARAMETER_ID_T" AS VARRAY(2500) OF VARCHAR2(8)
TYPE "DESC_VALS_ALLOWED_T" AS TABLE OF VARCHAR2(8)
}}

both of which appear as JDBC array types but attempting to register both means the last one "wins" and the other generates an error - i.e.
{{registerColumnType(Types.ARRAY, "desc_vals_allowed_t" );
registerColumnType(Types.ARRAY, "parameter_id_t" ); }}

gives

Schema-validation: wrong column type encountered in column [DESC_VALS_ALLOWED] in table [SHM.DESCRIPTOR]; found desc_vals_allowed_t (Types#OTHER), but expecting parameter_id_t (Types#ARRAY)