Facebook graph api m.mid vs m.id

Question

I'm retrieving messages from my page, but notice that the messages have two different id types.

on most of the messages they have an id as such:

"id": "m_id.363733227087070", 

however some of them are formated as

"id": "m_mid.1374165333681:48689d90e8f7fa5e77", 

What is the difference between m_mid and m_id? I cannot find any documentation on why some messages have an ID that is m_mid and some are m_id. Additionally, they m_mid has some sort of hashed number after it, any idea what this hex represents??

Answer 1

Did you find a definite answer for this?

From my observation, the first message in a conversation has id with the format m_id.<numeric id>. All subsequent messages have id with the format m_mid.<numeric id>:<hex hash>