optic potic otpic topic ptoic tpoic opitc poitc oiptc ioptc piotc ipotc otipc toipc oitpc iotpc tiopc itopc ptioc tpioc pitoc iptoc tipoc itpoc optci potci otpci topci ptoci tpoci opcti pocti ocpti copti pcoti cpoti otcpi tocpi octpi cotpi tcopi ctopi ptcoi tpcoi pctoi cptoi tcpoi ctpoi opict poict oipct iopct pioct ipoct opcit pocit ocpit copit pcoit cpoit oicpt iocpt ocipt coipt icopt ciopt picot ipcot pciot cpiot icpot cipot oticp toicp oitcp iotcp tiocp itocp otcip tocip octip cotip tcoip ctoip oictp ioctp ocitp coitp icotp ciotp ticop itcop tciop ctiop ictop citop ptico tpico pitco iptco tipco itpco ptcio tpcio pctio cptio tcpio ctpio picto ipcto pcito cpito icpto cipto ticpo itcpo tcipo ctipo ictpo citpo
Note: these 'words' (valid or invalid) are all the permutations of the word optic. These words are obtained by scrambling the letters in optic.