rivas irvas rvias vrias ivras viras riavs iravs raivs arivs iarvs airvs rvais vrais ravis arvis varis avris ivars viars iavrs aivrs vairs avirs rivsa irvsa rvisa vrisa ivrsa virsa risva irsva rsiva sriva isrva sirva rvsia vrsia rsvia srvia vsria svria ivsra visra isvra sivra vsira svira riasv irasv raisv arisv iarsv airsv risav irsav rsiav sriav israv sirav rasiv arsiv rsaiv sraiv asriv sariv iasrv aisrv isarv siarv asirv sairv rvasi vrasi ravsi arvsi varsi avrsi rvsai vrsai rsvai srvai vsrai svrai rasvi arsvi rsavi sravi asrvi sarvi vasri avsri vsari svari asvri savri ivasr viasr iavsr aivsr vaisr avisr ivsar visar isvar sivar vsiar sviar iasvr aisvr isavr siavr asivr saivr vasir avsir vsair svair asvir savir
Note: these 'words' (valid or invalid) are all the permutations of the word rivas. These words are obtained by scrambling the letters in rivas.