brelk rbelk berlk ebrlk reblk erblk brlek rblek blrek lbrek rlbek lrbek belrk eblrk blerk lberk elbrk lebrk relbk erlbk rlebk lrebk elrbk lerbk brekl rbekl berkl ebrkl rebkl erbkl brkel rbkel bkrel kbrel rkbel krbel bekrl ebkrl bkerl kberl ekbrl kebrl rekbl erkbl rkebl krebl ekrbl kerbl brlke rblke blrke lbrke rlbke lrbke brkle rbkle bkrle kbrle rkble krble blkre lbkre bklre kblre lkbre klbre rlkbe lrkbe rklbe krlbe lkrbe klrbe belkr eblkr blekr lbekr elbkr lebkr beklr ebklr bkelr kbelr ekblr keblr blker lbker bkler kbler lkber klber elkbr lekbr eklbr kelbr lkebr klebr relkb erlkb rlekb lrekb elrkb lerkb reklb erklb rkelb krelb ekrlb kerlb rlkeb lrkeb rkleb krleb lkreb klreb elkrb lekrb eklrb kelrb lkerb klerb
Note: these 'words' (valid or invalid) are all the permutations of the word brelk. These words are obtained by scrambling the letters in brelk.