!= or <>

I know this has been posted, put I cant find it with the search feature of
the web site of Postgresql.org.
Which is the best approach to put in a check constraint
    col <> something
    col != something
?

Saludos... :-)

--
El mejor sistema operativo es aquel que te da de comer.
Cuida tu dieta.
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Martin Marques                  |        mmarques@unl.edu.ar
Programador, Administrador      |       Centro de Telematica
                       Universidad Nacional
                            del Litoral
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