Under what cirmcustances are BBM messages marked as (R)ead?

I am trying to find out if BBM messages I receive are marked with the "R" on the sender's device under each of these circumstances:

1. In an open BBM chat displayed on my screen
2. In an open BBM chat but the screen has timed out and is locked
3. In an open BBM chat but switched to another app
4. In an open BBM chat but switched to my inbox and reading the BBM's first line
5. Closed but not ended a BBM chat; reading the 1st line of the BBM in the inbox

Thanks for any tips...

Good question. I'll take the ones I think I've observed.

I'm not completely sure about this, but for #2 I think if the screen isn't locked, the act that wakes it up does not cause a change from D to R (I'm going by the dots not turning grey.)

I'm not sure how #4 and #5 are different. If you're reading on the page that shows your chats, contacts, groups, etc. the message stays D. If you open a chat, it changes to R.

Thanks raino. You're right about 4 & 5. I think BBM is always open so that makes #5 the same as #4.

I always thought that as long as the chat is open any messages received would show up as read, but you may have a point.

The messages are marked as read upon user interaction.
If you get the message you will see a little dot to the left of it;

Yellow is new and unread
gray is read

as long as the dot is yellow the "R" isn't send. When you press any key, it will turn gray and your chat partner will see the "R"

what about if you click on, mark prior opening?

Will that be marked as read or sent on the senders bbm