nurds unrds nruds rnuds urnds runds nudrs undrs ndurs dnurs udnrs dunrs nrdus rndus ndrus dnrus rdnus drnus urdns rudns udrns durns rduns druns nursd unrsd nrusd rnusd urnsd runsd nusrd unsrd nsurd snurd usnrd sunrd nrsud rnsud nsrud snrud rsnud srnud ursnd rusnd usrnd surnd rsund srund nudsr undsr ndusr dnusr udnsr dunsr nusdr unsdr nsudr snudr usndr sundr ndsur dnsur nsdur sndur dsnur sdnur udsnr dusnr usdnr sudnr dsunr sdunr nrdsu rndsu ndrsu dnrsu rdnsu drnsu nrsdu rnsdu nsrdu snrdu rsndu srndu ndsru dnsru nsdru sndru dsnru sdnru rdsnu drsnu rsdnu srdnu dsrnu sdrnu urdsn rudsn udrsn dursn rdusn drusn ursdn rusdn usrdn surdn rsudn srudn udsrn dusrn usdrn sudrn dsurn sdurn rdsun drsun rsdun srdun dsrun sdrun
Note: these 'words' (valid or invalid) are all the permutations of the word nurds. These words are obtained by scrambling the letters in nurds.