Issues creating new conversation

[Kenneth Feldt]

We are having some issues in creating new conversations from our mobile website.

We use the API as described at https://canvas.instructure.com/doc/api/conversations.html -- but we often find messages attached to existing conversations even though we clearly do not pass a conversation ID in the string and are not using the add_message URL segment. We are setting the context code to the course ID.

There is a phrase in the API docs for conversations that describe the 'subject' field:

"The subject of the conversation. This is ignored when reusing a conversation." 

Under what conditions are conversations re-used --- is this some server based context that remembers an active conversation? 

Is a re-usable conversation some kind of binding among recipients? 

If so, does the conversation among three students retain the same subject for the duration of the semester?

So I guess I am looking for some non-API docs that describe just what a conversation is, and how to create a new one among the same set of recipients.