British spelling vs unuseable

British spelling is a noun but unuseable is not a noun.

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

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

British spelling (adjective)	unuseable (adjective)
	not capable of being used