dtank tdank datnk adtnk tadnk atdnk dtnak tdnak dntak ndtak tndak ntdak dantk adntk dnatk ndatk andtk nadtk tandk atndk tnadk ntadk antdk natdk dtakn tdakn datkn adtkn tadkn atdkn dtkan tdkan dktan kdtan tkdan ktdan daktn adktn dkatn kdatn akdtn kadtn takdn atkdn tkadn ktadn aktdn katdn dtnka tdnka dntka ndtka tndka ntdka dtkna tdkna dktna kdtna tkdna ktdna dnkta ndkta dknta kdnta nkdta kndta tnkda ntkda tknda ktnda nktda kntda dankt adnkt dnakt ndakt andkt nadkt daknt adknt dkant kdant akdnt kadnt dnkat ndkat dknat kdnat nkdat kndat ankdt nakdt akndt kandt nkadt knadt tankd atnkd tnakd ntakd antkd natkd taknd atknd tkand ktand aktnd katnd tnkad ntkad tknad ktnad nktad kntad anktd naktd akntd kantd nkatd knatd
Note: these 'words' (valid or invalid) are all the permutations of the word dtank. These words are obtained by scrambling the letters in dtank.