reist erist riest irest eirst ierst resit ersit rseit sreit esrit serit riset irset rsiet sriet isret siret eisrt iesrt esirt seirt isert siert reits erits riets irets eirts ierts retis ertis rteis treis etris teris rites irtes rties tries itres tires eitrs ietrs etirs teirs iters tiers resti ersti rseti sreti esrti serti retsi ertsi rtesi tresi etrsi tersi rstei srtei rtsei trsei strei tsrei estri setri etsri tesri steri tseri riste irste rsite srite isrte sirte ritse irtse rtise trise itrse tirse rstie srtie rtsie trsie strie tsrie istre sitre itsre tisre stire tsire eistr iestr esitr seitr isetr sietr eitsr ietsr etisr teisr itesr tiesr estir setir etsir tesir steir tseir ister siter itser tiser stier tsier
Note: these 'words' (valid or invalid) are all the permutations of the word reist. These words are obtained by scrambling the letters in reist.