Expansion Tank no cold mark??

[sleighty]

Hi Everyone

just a quick one - there isn't a cold mark on my expansion tank. I assume its a pattern one. Can anyone tell me approx how high the coolant level should be or does someone have a pic. Its a 96 318ti M44. I've filled it to the middle of the tank numerous times and it always seems to find its natural level and no lower. However I think this is quite low.

I just want re-assurance really that the cold mark is quite low, I don't think its leaking from anywhere as there is no sign of it.