courb ocurb cuorb ucorb oucrb uocrb corub ocrub croub rcoub orcub rocub curob ucrob cruob rcuob urcob rucob ourcb uorcb orucb roucb urocb ruocb coubr ocubr cuobr ucobr oucbr uocbr cobur ocbur cbour bcour obcur bocur cubor ucbor cbuor bcuor ubcor bucor oubcr uobcr obucr boucr ubocr buocr corbu ocrbu crobu rcobu orcbu rocbu cobru ocbru cboru bcoru obcru bocru crbou rcbou cbrou bcrou rbcou brcou orbcu robcu obrcu borcu rbocu brocu curbo ucrbo crubo rcubo urcbo rucbo cubro ucbro cburo bcuro ubcro bucro crbuo rcbuo cbruo bcruo rbcuo brcuo urbco rubco ubrco burco rbuco bruco ourbc uorbc orubc roubc urobc ruobc oubrc uobrc oburc bourc uborc buorc orbuc robuc obruc boruc rbouc brouc urboc ruboc ubroc buroc rbuoc bruoc
Note: these 'words' (valid or invalid) are all the permutations of the word courb. These words are obtained by scrambling the letters in courb.