Best practices, scurity SQL Server port 1433

I want to know, what are the best practices about the 1433 port.

In some blogs I saw that for security is necessary change the port 1433 and in other no is necessary. Some one have official informations or links about  it.

Thanks

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Carlos Ignacio Aguero. DBA SQL Server. Toda mi respeto al pueblo Peruano por la ayuda prestada en la guerra de Malvinas.