British spelling vs program optimisation

British spelling and program optimisation both are nouns.

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

British spelling (noun)	program optimisation (noun)
English orthography used in the UK, Ireland and most of the Commonwealth (characterized by 'analyse', 'centre' and 'useable')	the process of modifying a software system to make some aspect of it work more efficiently or use fewer resources.