Normal hair curl. Khasil, do you try to verify with some error references if there are any known errors of the kind you're seeing? I ask this because that is how we all have learned what is and what is not an error. I can see why you may have thought this curl was something different, there is a vague shape similarity. I checked this link:
http://coppercoins.com/advsearch.php by putting in 2006 and D then checking obverse douling it tells you there are no known errors by saying you didn't enter the data...if there were an example would pop up and you match to the pix. Check it out.