pfeld fpeld pefld epfld fepld efpld pfled fpled plfed lpfed flped lfped pelfd eplfd plefd lpefd elpfd lepfd felpd eflpd flepd lfepd elfpd lefpd pfedl fpedl pefdl epfdl fepdl efpdl pfdel fpdel pdfel dpfel fdpel dfpel pedfl epdfl pdefl dpefl edpfl depfl fedpl efdpl fdepl dfepl edfpl defpl pflde fplde plfde lpfde flpde lfpde pfdle fpdle pdfle dpfle fdple dfple pldfe lpdfe pdlfe dplfe ldpfe dlpfe fldpe lfdpe fdlpe dflpe ldfpe dlfpe peldf epldf pledf lpedf elpdf lepdf pedlf epdlf pdelf dpelf edplf deplf pldef lpdef pdlef dplef ldpef dlpef eldpf ledpf edlpf delpf ldepf dlepf feldp efldp fledp lfedp elfdp lefdp fedlp efdlp fdelp dfelp edflp deflp fldep lfdep fdlep dflep ldfep dlfep eldfp ledfp edlfp delfp ldefp dlefp
Note: these 'words' (valid or invalid) are all the permutations of the word pfeld. These words are obtained by scrambling the letters in pfeld.