In Microsoft User Data Folder why is there a folder "Office X Identities"

Although I have Office 2004, I upgraded from Office v.X. I was under the impression that Office X Identities was an artifact of my earlier installation. I learn something new every day.

For your question, Office allows each user to have multiple "identities," each of which is a set of settings such as email settings. Because every file in my Office X Indentities folder is an Entourage file, I believe that only Entourage uses multiple identies. However, I am not certain.