stuhb tsuhb suthb usthb tushb utshb sthub tshub shtub hstub thsub htsub suhtb ushtb shutb hsutb uhstb hustb tuhsb uthsb thusb htusb uhtsb hutsb stubh tsubh sutbh ustbh tusbh utsbh stbuh tsbuh sbtuh bstuh tbsuh btsuh subth usbth sbuth bsuth ubsth busth tubsh utbsh tbush btush ubtsh butsh sthbu tshbu shtbu hstbu thsbu htsbu stbhu tsbhu sbthu bsthu tbshu btshu shbtu hsbtu sbhtu bshtu hbstu bhstu thbsu htbsu tbhsu bthsu hbtsu bhtsu suhbt ushbt shubt hsubt uhsbt husbt subht usbht sbuht bsuht ubsht busht shbut hsbut sbhut bshut hbsut bhsut uhbst hubst ubhst buhst hbust bhust tuhbs uthbs thubs htubs uhtbs hutbs tubhs utbhs tbuhs btuhs ubths buths thbus htbus tbhus bthus hbtus bhtus uhbts hubts ubhts buhts hbuts bhuts
Note: these 'words' (valid or invalid) are all the permutations of the word stuhb. These words are obtained by scrambling the letters in stuhb.