nurls unrls nruls rnuls urnls runls nulrs unlrs nlurs lnurs ulnrs lunrs nrlus rnlus nlrus lnrus rlnus lrnus urlns rulns ulrns lurns rluns lruns nursl unrsl nrusl rnusl urnsl runsl nusrl unsrl nsurl snurl usnrl sunrl nrsul rnsul nsrul snrul rsnul srnul ursnl rusnl usrnl surnl rsunl srunl nulsr unlsr nlusr lnusr ulnsr lunsr nuslr unslr nsulr snulr usnlr sunlr nlsur lnsur nslur snlur lsnur slnur ulsnr lusnr uslnr sulnr lsunr slunr nrlsu rnlsu nlrsu lnrsu rlnsu lrnsu nrslu rnslu nsrlu snrlu rsnlu srnlu nlsru lnsru nslru snlru lsnru slnru rlsnu lrsnu rslnu srlnu lsrnu slrnu urlsn rulsn ulrsn lursn rlusn lrusn ursln rusln usrln surln rsuln sruln ulsrn lusrn uslrn sulrn lsurn slurn rlsun lrsun rslun srlun lsrun slrun
Note: these 'words' (valid or invalid) are all the permutations of the word nurls. These words are obtained by scrambling the letters in nurls.