You can have the code sent to yourself if you'd like to see what your referals see. It's a link to the installer, the referal code, and whatever custom message you'd like to attach (for example, "Hi ESOFriendCharacterName, it's ESOMyCharName! Here's a trial link for FFXIV! My char name there is My Name and I'm on MyServer server. Hope to see you soon!"); besides the information you provide in the customized part, your friend gets no info about you. How muchinfo you need to provide is up to you and whether you and your friend already communicate via other means.