Documentation bug in 8.3?

Reading through the text search data type docs:

    http://www.postgresql.org/docs/8.3/static/datatype-textsearch.html#DATATYPE-TSVECTOR

it says:

    Optionally, integer position(s) can be attached to any or all of the
    lexemes:

    SELECT 'a:1 fat:2 cat:3 sat:4 on:5 a:6 mat:7 and:8 ate:9 a:10 fat:11
    rat:12'::tsvector;
                                      tsvector
    -------------------------------------------------------------------------------

     'a':1,6,10 'on':5 'and':8 'ate':9 'cat':3 'fat':2,11 'mat':7 'rat':12
    'sat':4

    A position normally indicates the source word's location in the
    document. Positional information can be used for proximity ranking.
    Position values can range from 1 to 16383; larger numbers are silently
    clamped to 16383. Duplicate position entries are discarded.
                      ----------------------------------------

However in my testing of 8.3 duplicate position entries are not
discarded:

    test=> SELECT 'a:1 b:1'::tsvector;
      tsvector
    -------------
     'a':1 'b':1
    (1 row)

--
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://postgres.enterprisedb.com

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