You are encouraged to join if your last name is reasonably similar to 'Denning', or if you are a close Y-DNA match with somebody who is. You are welcome to join if you need to compare your Family Finder (autosomal) results with Y-DNA testers from the 'Advanced Matches' page. Under our 'Links' section there are linked several other projects which may suit your particular case more, and it is up to your discretion to choose which is most appropriate. If you are a Denning, descended from a Denning, a close STR match to a Denning (within 1,000-ish years), or if in any of these cases the spelling has no closer match with another project, then stay here. It is recommended for all participants to at least have "Family Finder" (or an autosomal transfer from another company; check our "Links" section to find out more), to compare against those who do have Y-chromosomal DNA (patrilineal) results, and allow others to compare with your own results for such, and to that end it is most helpful if you do have Y-DNA results (as a male) and preferably this is with Big-Y700. As with all FamilyTreeDNA projects, no contact details or personal information will be publicised through the tools provided by FamilyTreeDNA. By joining, your basic Y-DNA STR marker+haplogroup results and/or mtDNA haplogroup results are automatically publicised in the DNA Results pages alongside your last name and earliest known matrilineal and/or patrilineal ancestors and their respective birth+death dates and places. So that the administrator can effectively group your results, your project preferences for her will need to be set to at least Limited (not Minimal).