htcol thcol hctol chtol tchol cthol htocl thocl hotcl ohtcl tohcl othcl hcotl chotl hoctl ohctl cohtl ochtl tcohl ctohl tochl otchl cothl octhl htclo thclo hctlo chtlo tchlo cthlo htlco thlco hltco lhtco tlhco lthco hclto chlto hlcto lhcto clhto lchto tclho ctlho tlcho ltcho cltho lctho htolc tholc hotlc ohtlc tohlc othlc htloc thloc hltoc lhtoc tlhoc lthoc holtc ohltc hlotc lhotc olhtc lohtc tolhc otlhc tlohc ltohc olthc lothc hcolt cholt hoclt ohclt cohlt ochlt hclot chlot hlcot lhcot clhot lchot holct ohlct hloct lhoct olhct lohct colht oclht cloht lcoht olcht locht tcolh ctolh toclh otclh cotlh octlh tcloh ctloh tlcoh ltcoh cltoh lctoh tolch otlch tloch ltoch oltch lotch colth oclth cloth lcoth olcth locth
Note: these 'words' (valid or invalid) are all the permutations of the word htcol. These words are obtained by scrambling the letters in htcol.