imfer mifer ifmer fimer mfier fmier imefr miefr iemfr eimfr meifr emifr ifemr fiemr iefmr eifmr feimr efimr mfeir fmeir mefir emfir femir efmir imfre mifre ifmre fimre mfire fmire imrfe mirfe irmfe rimfe mrife rmife ifrme firme irfme rifme frime rfime mfrie fmrie mrfie rmfie frmie rfmie imerf mierf iemrf eimrf meirf emirf imref miref irmef rimef mrief rmief iermf eirmf iremf riemf erimf reimf merif emrif mreif rmeif ermif remif iferm fierm iefrm eifrm feirm efirm ifrem firem irfem rifem friem rfiem ierfm eirfm irefm riefm erifm reifm ferim efrim freim rfeim erfim refim mferi fmeri mefri emfri femri efmri mfrei fmrei mrfei rmfei frmei rfmei merfi emrfi mrefi rmefi ermfi remfi fermi efrmi fremi rfemi erfmi refmi
Note: these 'words' (valid or invalid) are all the permutations of the word imfer. These words are obtained by scrambling the letters in imfer.