Session ID Usage

A

Yes 

C

Yes

Yes

Not consistent

E

Yes

Little e

Yes

F

Yes

H

Yes

Yes

Yes

“R” session ID message contains RTH only high/low prices.

“G” session ID message contains ETH only high/low prices.

Blank session ID contains combined ETH and RTH high/low prices.

I

Yes

J

Yes

Yes

“R” session ID message contains RTH summary data only.

Blank session ID messages contains combined ETH and RTH summary data.

N

Yes

Q

Yes

Yes

Not consistent Session ID is meaningful for category Q limit messages.

Little t

Yes

U

Yes

V

Yes

Yes

Yes

“R” session ID message contains RTH only volume.

“G” session ID message contains ETH only volume.

Blank session ID message contains combined

ETH and RTH volume.

Little v

Yes

X

Yes

Yes

Y

Yes

Z

Yes

Yes

Not consistent