British spelling vs optimisation

British spelling and optimisation both are nouns.

Word	Noun	Adjective	Verb	Adverb
British spelling	Yes	No	No	No
optimisation	Yes	No	No	No

British spelling (noun)	optimisation (noun)
English orthography used in the UK, Ireland and most of the Commonwealth (characterized by 'analyse', 'centre' and 'useable')	the act of rendering optimal