isque sique iqsue qisue sqiue qsiue isuqe siuqe iusqe uisqe suiqe usiqe iquse qiuse iuqse uiqse quise uqise squie qsuie suqie usqie qusie uqsie isqeu siqeu iqseu qiseu sqieu qsieu isequ siequ iesqu eisqu seiqu esiqu iqesu qiesu ieqsu eiqsu qeisu eqisu sqeiu qseiu seqiu esqiu qesiu eqsiu isueq siueq iuseq uiseq suieq usieq iseuq sieuq iesuq eisuq seiuq esiuq iuesq uiesq ieusq eiusq ueisq euisq sueiq useiq seuiq esuiq uesiq eusiq iques qiues iuqes uiqes quies uqies iqeus qieus iequs eiqus qeius eqius iueqs uieqs ieuqs eiuqs ueiqs euiqs queis uqeis qeuis equis ueqis euqis squei qsuei suqei usqei qusei uqsei sqeui qseui sequi esqui qesui eqsui sueqi useqi seuqi esuqi uesqi eusqi quesi uqesi qeusi equsi ueqsi euqsi
Note: these 'words' (valid or invalid) are all the permutations of the word isque. These words are obtained by scrambling the letters in isque.