scaff csaff sacff ascff casff acsff scfaf csfaf sfcaf fscaf cfsaf fcsaf safcf asfcf sfacf fsacf afscf fascf cafsf acfsf cfasf fcasf afcsf facsf scaff csaff sacff ascff casff acsff scfaf csfaf sfcaf fscaf cfsaf fcsaf safcf asfcf sfacf fsacf afscf fascf cafsf acfsf cfasf fcasf afcsf facsf scffa csffa sfcfa fscfa cfsfa fcsfa scffa csffa sfcfa fscfa cfsfa fcsfa sffca fsfca sffca fsfca ffsca ffsca cffsa fcfsa cffsa fcfsa ffcsa ffcsa saffc asffc sfafc fsafc afsfc fasfc saffc asffc sfafc fsafc afsfc fasfc sffac fsfac sffac fsfac ffsac ffsac affsc fafsc affsc fafsc ffasc ffasc caffs acffs cfafs fcafs afcfs facfs caffs acffs cfafs fcafs afcfs facfs cffas fcfas cffas fcfas ffcas ffcas affcs fafcs affcs fafcs ffacs ffacs
Note: these 'words' (valid or invalid) are all the permutations of the word scaff. These words are obtained by scrambling the letters in scaff.