class lcass calss aclss lacss alcss clsas lcsas cslas sclas lscas slcas casls acsls csals scals ascls sacls lascs alscs lsacs slacs aslcs salcs class lcass calss aclss lacss alcss clsas lcsas cslas sclas lscas slcas casls acsls csals scals ascls sacls lascs alscs lsacs slacs aslcs salcs clssa lcssa cslsa sclsa lscsa slcsa clssa lcssa cslsa sclsa lscsa slcsa cssla scsla cssla scsla sscla sscla lssca slsca lssca slsca sslca sslca cassl acssl csasl scasl ascsl sacsl cassl acssl csasl scasl ascsl sacsl cssal scsal cssal scsal sscal sscal asscl sascl asscl sascl ssacl ssacl lassc alssc lsasc slasc aslsc salsc lassc alssc lsasc slasc aslsc salsc lssac slsac lssac slsac sslac sslac asslc saslc asslc saslc ssalc ssalc
Note: these 'words' (valid or invalid) are all the permutations of the word class. These words are obtained by scrambling the letters in class.