Anton gave his parents' address, as that was the place he was most likely to return to. The uncertain nature of the war, he felt more comfortable giving that than the barracks address anyhow.
"I was pleased to find this place," Anton offered, by means of making a bit of conversation while she filled out his library form. "I read a lot of English books at home, and I miss them. I know I should likely be reading more French books to practice - my French is still fairly bad."