I was granted green card in 2007 (dated 2006). After I got my green card some friends told me that if I wanted to travel I would need a national passport and not a refugee travel document as I had done previously. I did not think about it much, and got a national passport; even though I have no intention of returning to the country of origin. I traveled on the national passport to Europe only once. Recently when I was talking to someone else I was told that I should not have applied for the national passport as that can become an issue for my citizenship. I am not sure what to do. I can immediately apply for a an RTD as I do not mind the cost. But should I tell USCIS that I had been misled into believing that after getting my GC I could not apply for an RTD and had to travel on a national passport? I am worried about it and do not want it to become an issue in the future. Any help is appreciated. Thanks.