redundants indexes can be created

Hi guys,

Why postgres does not disallow creating redundants indexes ? Is it the
same behaviour in postgresql 8.3 ?

postgres=# \d t1
             Table "public.t1"
Column |         Type          | Modifiers
--------+-----------------------+-----------
id     | integer               | not null
name   | character varying(20) |
Indexes:
    "t1_pkey" PRIMARY KEY, btree (id)
    "idx" btree (id)
    "idx2" btree (id)
    "idx3" btree (id)
    "idx4" btree (id)
    "idx5" btree (id)


Regards
--
Cyril SCETBON