You don't have to do it but you can. I have never put DD's middle name in with VA, but this year with CO I did put her initial in and it has tagged onto the first name. So if your name was Susan Jane Smith, you would enter Susan J Smith and on your ticket and confirmation it will show as SUSANJ SMITH. This is perfectly normal but understandably plenty folk worry about it. There is a section on their website that explains it and I will try and find it. If I do, I will post you a link