The best 2 and 3 letter keyword domain names I want are unavailable. E.g keyword1keyword2.com
However, I can get keyword1keyword2rus.com and keyword1-keyword2-r-us.com
("rus" as in "are us"). This is just an example of a short abbreviation I could add to a domain name. It isn't actually the one I would use.
Are there major disadvantages to using a domain name made up with excellent key words and an abbreviated term like "rus"? Fro example, would it have a major impact on search engine ranking?