Absolutely. Simply go to the 'change contact details', which can be located under settings from the 'Your Account' page.
Here you can click on the 'pledge anonymously' check box. You can still get your name in the back of the book whilst being anonymous online, just add your name in the back by following the steps above. Please note that if you press the 'pledge anonymously' check box after you have added the names in the back then the names won't be removed.
If you don't want your name in the back of the book, you can simply delete the name in the Your Account's section. Click here to learn more.