ruing uring riung irung uirng iurng runig urnig rnuig nruig unrig nurig rinug irnug rniug nriug inrug nirug uinrg iunrg unirg nuirg inurg niurg ruign urign riugn irugn uirgn iurgn rugin urgin rguin gruin ugrin gurin rigun irgun rgiun griun igrun girun uigrn iugrn ugirn guirn igurn giurn rungi urngi rnugi nrugi unrgi nurgi rugni urgni rguni gruni ugrni gurni rngui nrgui rgnui grnui ngrui gnrui ungri nugri ugnri gunri nguri gnuri ringu irngu rnigu nrigu inrgu nirgu rignu irgnu rginu grinu igrnu girnu rngiu nrgiu rgniu grniu ngriu gnriu ingru nigru ignru ginru ngiru gniru uingr iungr unigr nuigr inugr niugr uignr iugnr uginr guinr igunr giunr ungir nugir ugnir gunir nguir gnuir ingur nigur ignur ginur ngiur gniur
Note: these 'words' (valid or invalid) are all the permutations of the word ruing. These words are obtained by scrambling the letters in ruing.