Yes. Pick a nickname for yourself from your profile page by clicking on the "Edit Profile" link. From there, you can change your display name. With a nickname, you don't reveal your email address or Yahoo! ID. This helps to protect your account and reduce spam.

Using a nickname also gives you a consistent identity across all of Yahoo!, making it easier for you to participate, share, and gain recognition across multiple Yahoo! sites.

Unless you choose to display your Yahoo! ID or post content as "A Yahoo! Contributor", your nickname displays wherever your Yahoo! identity appears.