utbra tubra ubtra butra tbura btura utrba turba urtba rutba truba rtuba ubrta burta urbta rubta bruta rbuta tbrua btrua trbua rtbua brtua rbtua utbar tubar ubtar butar tbuar btuar utabr tuabr uatbr autbr taubr atubr ubatr buatr uabtr aubtr bautr abutr tbaur btaur tabur atbur batur abtur utrab turab urtab rutab truab rtuab utarb tuarb uatrb autrb taurb aturb uratb ruatb uartb aurtb rautb arutb traub rtaub tarub atrub ratub artub ubrat burat urbat rubat bruat rbuat ubart buart uabrt aubrt baurt aburt urabt ruabt uarbt aurbt raubt arubt braut rbaut barut abrut rabut arbut tbrau btrau trbau rtbau brtau rbtau tbaru btaru tabru atbru batru abtru trabu rtabu tarbu atrbu ratbu artbu bratu rbatu bartu abrtu rabtu arbtu
Note: these 'words' (valid or invalid) are all the permutations of the word utbra. These words are obtained by scrambling the letters in utbra.