neper enper npeer pneer epner pener neepr enepr neepr enepr eenpr eenpr npeer pneer neper enper pener epner epenr peenr eepnr eepnr peenr epenr nepre enpre npere pnere epnre penre nerpe enrpe nrepe rnepe ernpe renpe npree pnree nrpee rnpee prnee rpnee eprne perne erpne repne prene rpene neerp enerp neerp enerp eenrp eenrp nerep enrep nreep rneep ernep renep nerep enrep nreep rneep ernep renep eernp eernp erenp reenp erenp reenp npere pnere nepre enpre penre epnre npree pnree nrpee rnpee prnee rpnee nerpe enrpe nrepe rnepe ernpe renpe perne eprne prene rpene erpne repne epern peern eeprn eeprn peern epern epren peren erpen repen preen rpeen eerpn eerpn erepn reepn erepn reepn peren epren preen rpeen erpen repen
Note: these 'words' (valid or invalid) are all the permutations of the word neper. These words are obtained by scrambling the letters in neper.