3. Use the numbers obtained by application of rule 2 to designate the location of substituent group (取代基定位) The parent name is placed last The substituent group name is placed first Numbers are separated from words by a hyphen3. Use the numbers obtained by application of rule 2 to designate the location of substituent group. (取代基定位） • The parent name is placed last. • The substituent group name is placed first. • Numbers are separated from words by a hyphen