upbow pubow ubpow bupow pbuow bpuow upobw puobw uopbw oupbw poubw opubw ubopw buopw uobpw oubpw boupw obupw pbouw bpouw pobuw opbuw bopuw obpuw upbwo pubwo ubpwo bupwo pbuwo bpuwo upwbo puwbo uwpbo wupbo pwubo wpubo ubwpo buwpo uwbpo wubpo bwupo wbupo pbwuo bpwuo pwbuo wpbuo bwpuo wbpuo upowb puowb uopwb oupwb pouwb opuwb upwob puwob uwpob wupob pwuob wpuob uowpb ouwpb uwopb wuopb owupb woupb powub opwub pwoub wpoub owpub wopub ubowp buowp uobwp oubwp bouwp obuwp ubwop buwop uwbop wubop bwuop wbuop uowbp ouwbp uwobp wuobp owubp woubp bowup obwup bwoup wboup owbup wobup pbowu bpowu pobwu opbwu bopwu obpwu pbwou bpwou pwbou wpbou bwpou wbpou powbu opwbu pwobu wpobu owpbu wopbu bowpu obwpu bwopu wbopu owbpu wobpu
Note: these 'words' (valid or invalid) are all the permutations of the word upbow. These words are obtained by scrambling the letters in upbow.