the 'z' is the americanised version of the spelling, so still correct!
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Fri 19 May 2006, 11:13,
archived)
The 'z' is usually the English version in most words.
Notable exceptions are words derived from French, which have an 's'.
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Fri 19 May 2006, 11:16,
archived)
light amplification by stimulated emission of radiation
there can be no Z
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Fri 19 May 2006, 11:22,
archived)
I know - but some people do spell it with a Z - mostly Americans
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Fri 19 May 2006, 11:30,
archived)