When the Conversations feature is used, it should be required to mention a story, defect, test, etc.

This will ensure that, when a recipient receives an email notification about the conversation, they will understand what item the discussion pertains to.

Background: Today, I received an email regarding a new conversation that I was part of. Trying to understand why there was no reference to a story or defect, I learned that this happened because the originator of the conversation accidentally clicked the "x" next to the work item - thus removing it from the conversation. (In my opinion, this should be required in order to save the conversation.)