Lets say I own two domains that point to the same content.  foobar.coma.foobar.comb.foobar.com  barfoo.coma. and b. and testing servers, barfoo.com is a second domain that allows censored users to access the website.I would like no hostname other than foobar.com to appear in Google searches. Is there a way of marking the other sites as copies?
Is it possible to denote a domain is a copy of another domain?
seo;domains
We get this question a lot.Use canonical tags (at least). A canonical tag simply points to the original page. It allows Google to know which page is to be indexed.https://support.google.com/webmasters/answer/139066?hl=enLook for the heading Indicate the preferred URL with the rel=canonical link element for an example.There is also other good information on this page. It is a good one to bookmark for the future.