We used the rules given in Templeton et al (1987) and Templeton and Sing (1993) to define anevolutionary clade hierarchy upon the intraspecific haplotype network. The method starts from the tips of the network by nesting haplotypes (‘zero step clades’) separated by one mutational change within ‘one-step clades’,and proceeds step by step to identify higher level clades until the final level of nesting includes the entire network.