trabs rtabs tarbs atrbs ratbs artbs trbas rtbas tbras btras rbtas brtas tabrs atbrs tbars btars abtrs batrs rabts arbts rbats brats abrts barts trasb rtasb tarsb atrsb ratsb artsb trsab rtsab tsrab strab rstab srtab tasrb atsrb tsarb starb astrb satrb rastb arstb rsatb sratb asrtb sartb trbsa rtbsa tbrsa btrsa rbtsa brtsa trsba rtsba tsrba strba rstba srtba tbsra btsra tsbra stbra bstra sbtra rbsta brsta rsbta srbta bsrta sbrta tabsr atbsr tbasr btasr abtsr batsr tasbr atsbr tsabr stabr astbr satbr tbsar btsar tsbar stbar bstar sbtar abstr bastr asbtr sabtr bsatr sbatr rabst arbst rbast brast abrst barst rasbt arsbt rsabt srabt asrbt sarbt rbsat brsat rsbat srbat bsrat sbrat absrt basrt asbrt sabrt bsart sbart
Note: these 'words' (valid or invalid) are all the permutations of the word trabs. These words are obtained by scrambling the letters in trabs.