bourg oburg buorg uborg oubrg uobrg borug obrug broug rboug orbug robug burog ubrog bruog rbuog urbog rubog ourbg uorbg orubg roubg urobg ruobg bougr obugr buogr ubogr oubgr uobgr bogur obgur bgour gbour ogbur gobur bugor ubgor bguor gbuor ugbor gubor ougbr uogbr ogubr goubr ugobr guobr borgu obrgu brogu rbogu orbgu robgu bogru obgru bgoru gboru ogbru gobru brgou rbgou bgrou gbrou rgbou grbou orgbu rogbu ogrbu gorbu rgobu grobu burgo ubrgo brugo rbugo urbgo rubgo bugro ubgro bguro gburo ugbro gubro brguo rbguo bgruo gbruo rgbuo grbuo urgbo rugbo ugrbo gurbo rgubo grubo ourgb uorgb orugb rougb urogb ruogb ougrb uogrb ogurb gourb ugorb guorb orgub rogub ogrub gorub rgoub groub urgob rugob ugrob gurob rguob gruob
Note: these 'words' (valid or invalid) are all the permutations of the word bourg. These words are obtained by scrambling the letters in bourg.