Hin/Hix
From 2006.igem.org
The mutant Hix sites are found in [http://www.jbc.org/cgi/reprint/267/16/11183 The Effects of Symmetrical Recombination Site hixC on Hin Recombinase Function. Heon Man Lim et al.] on p 1185 while their performance is located on p 1187.