The Z255 and Subclades Project serves as a repository of data for those lineages that inherit the distinctive Z255 haplotype, which is mainly found throughout Great Britain and Ireland, but can also be found in Continental Europe, namely France, Norway, and Sweden. Z255 is also found in at least one sample in the Genome of the Netherlands (GoNL) project, and is located downstream of L21 and DF13.
 

This project has two, main subgroups: 

- Samples tested Z255+ and L159.2+
- Samples tested Z255+ and L159.2-

Furthermore, there seems to be a correlation between Z255 and having two C alleles and two G alleles on DYS464x. The modal for R1b1a2 is CCCG. This further supports Z255's status as an indicator of shared ancestry. 

For more information on the L21 Project - http://www.familytreedna.com/public/R-L21/default.aspx
For more information on the 464x Project - http://www.familytreedna.com/public/DYS464x%20ccgg/default.aspx
Discussion about Z255 and L159.2 can be found at our Yahoo! Groups forum - R-Z255 and Subclades Forum

This is a public project. The more we share data about our origins and test results, the better we can understand our families. When you join this project, you have granted permission to place your Y SNP and STR data into the public domain, from which it can never be retrieved. We do not publish your full given name or contact info.