title: What is IdentityPart in Orchard CMS good for?
body: <p>I havent found any mention in Orchard documentation about IdentityPart despite it being used in some main modules like Comments. I took a look at some relevant sources, but it didn't help me to fully understand it's purpose.</p>
  
  <p>So what's it for and when should I use it?</p>
  
  <p>Thanks in advance!</p>