ISO-8859-11 not in the IANA charset list

[Samphan Raruenrom <samphan@osdev.co.th>]

Hi,

I don't see ISO-8859-11 at http://www.iana.org/assignments/character-sets

 From http://en.wikipedia.org/wiki/ISO_8859-11
 > ISO-8859-11 is not a registered IANA charset name dispite
 > following the normal pattern for IANA charsets based on
 > the ISO 8859 series.

Why ISO-8859-11 is not registered?
Do someone need to register it?