A basic list of comments
A comment can contain an image or avatar
A comment can contain metadata about the comment, an arbitrary amount of metadata may be defined.
A comment can contain an list of actions a user may perform related to this comment.
A comment can contain a form to reply to a comment. This may have arbitrary content.
Comments can be collapsed, or hidden from view
A comment list can be threaded to showing the relationship between conversations
Comments can hide extra information unless a user shows intent to interact with a comment.