With the integration of the Yahoo! Address Book with your Yahoo! Messenger List, Yahoo! Messenger tries to attach a name to a Yahoo! ID whenever it's possible.

First, Yahoo! Messenger tries to get the information from the First and Last name fields in "My Contact Details." Next, if it still needs the information, it tries to find it in the Name entry in the Address/Contact Information section on the "Yahoo! Account Info" page.

This information is then sent to users whenever you send your contact details, usually when someone requests to add you to their Messenger List.

You can change your information in the "My Contact Details" section within Yahoo! Messenger. To change your name in the "My Contact Details" section:

1. Click the Messenger menu in Messenger.
2. Select My Contact Details. This will open a window allowing you to modify your contact information.
3. Enter the information you want modified in the First and Last name fields.
   Please note: The First and Last Name fields are required when sending contact information to another person.
4. Click Save & Close to save the changes made.

If you want something other than your full name to be displayed in the Instant Message window, enter something in either the First, Last or Nickname fields in the "My Contact Details" window.

Although your name or your nickname may be displayed in the Instant Message window, the person you're communicating with will only see what they've entered for you on their Contact or Messenger List. This could be your Yahoo! ID, your Name, or a Nickname they've entered for you.

If you want to send your updated contact information to someone, please follow these steps:

1. Click the Actions menu in Messenger and select Send My Contact Details.
2. Select the person or people you want to send your contact details and click Next.
3. Check the boxes in front of the information you want to send or update.
4. If any information is missing, click Edit My Contact Details to make the necessary modifications.

Please note: You only have the ability to update information on someone's contact list. You cannot remove information from any fields (such as First or Last name fields). The person must accept the update for their Contact List to be updated.