Post Forms Overview
Similar to mail forms, all post form pages are customizable, and have separate Compose and Read pages that you can modify. (You can also use form regions to remove and add pages for customization.)
A folder that contains posts is usually grouped by the Conversation field to keep related topics together. The Conversation field, also known as the ConversationTopic property in the Microsoft Outlook object model, is set based on the Subject field of a new post in the folder. All replies to this item inherit the Conversation field from the parent item. However, if the user changes the Subject field, the Conversation field is set to the new subject, which creates a new conversation.
For more information, see the following topics: