herbs ehrbs hrebs rhebs erhbs rehbs hebrs ehbrs hbers bhers ebhrs behrs hrbes rhbes hbres bhres rbhes brhes erbhs rebhs ebrhs berhs rbehs brehs hersb ehrsb hresb rhesb erhsb rehsb hesrb ehsrb hserb sherb eshrb sehrb hrseb rhseb hsreb shreb rsheb srheb ershb reshb esrhb serhb rsehb srehb hebsr ehbsr hbesr bhesr ebhsr behsr hesbr ehsbr hsebr shebr eshbr sehbr hbser bhser hsber shber bsher sbher ebshr beshr esbhr sebhr bsehr sbehr hrbse rhbse hbrse bhrse rbhse brhse hrsbe rhsbe hsrbe shrbe rshbe srhbe hbsre bhsre hsbre shbre bshre sbhre rbshe brshe rsbhe srbhe bsrhe sbrhe erbsh rebsh ebrsh bersh rbesh bresh ersbh resbh esrbh serbh rsebh srebh ebsrh besrh esbrh sebrh bserh sberh rbseh brseh rsbeh srbeh bsreh sbreh
Note: these 'words' (valid or invalid) are all the permutations of the word herbs. These words are obtained by scrambling the letters in herbs.