drack rdack darck adrck radck ardck drcak rdcak dcrak cdrak rcdak crdak dacrk adcrk dcark cdark acdrk cadrk racdk arcdk rcadk cradk acrdk cardk drakc rdakc darkc adrkc radkc ardkc drkac rdkac dkrac kdrac rkdac krdac dakrc adkrc dkarc kdarc akdrc kadrc rakdc arkdc rkadc kradc akrdc kardc drcka rdcka dcrka cdrka rcdka crdka drkca rdkca dkrca kdrca rkdca krdca dckra cdkra dkcra kdcra ckdra kcdra rckda crkda rkcda krcda ckrda kcrda dackr adckr dcakr cdakr acdkr cadkr dakcr adkcr dkacr kdacr akdcr kadcr dckar cdkar dkcar kdcar ckdar kcdar ackdr cakdr akcdr kacdr ckadr kcadr rackd arckd rcakd crakd acrkd carkd rakcd arkcd rkacd kracd akrcd karcd rckad crkad rkcad krcad ckrad kcrad ackrd cakrd akcrd kacrd ckard kcard
Note: these 'words' (valid or invalid) are all the permutations of the word drack. These words are obtained by scrambling the letters in drack.