treyf rteyf teryf etryf retyf ertyf tryef rtyef tyref ytref rytef yrtef teyrf etyrf tyerf yterf eytrf yetrf reytf erytf ryetf yretf eyrtf yertf trefy rtefy terfy etrfy retfy ertfy trfey rtfey tfrey ftrey rftey frtey tefry etfry tfery ftery eftry fetry refty erfty rfety frety efrty ferty tryfe rtyfe tyrfe ytrfe rytfe yrtfe trfye rtfye tfrye ftrye rftye frtye tyfre ytfre tfyre ftyre yftre fytre ryfte yrfte rfyte fryte yfrte fyrte teyfr etyfr tyefr ytefr eytfr yetfr tefyr etfyr tfeyr fteyr eftyr fetyr tyfer ytfer tfyer ftyer yfter fyter eyftr yeftr efytr feytr yfetr fyetr reyft eryft ryeft yreft eyrft yerft refyt erfyt rfeyt freyt efryt feryt ryfet yrfet rfyet fryet yfret fyret eyfrt yefrt efyrt feyrt yfert fyert
Note: these 'words' (valid or invalid) are all the permutations of the word treyf. These words are obtained by scrambling the letters in treyf.