The way it was build originally - this tracking field is auto-
populated with tracking or Label from the Shipping engine, but yes I
do agree we should provide a way to enter the fields.
As a matter of fact we need carefully review ALL Order fields we have
now and properly adjust which are editable and which are not since
right now it's a bit outdated I believe. I have already started
similar talk (in regards to all Order fields) in a separate
discussion. Alex, might remember that since it was hiom who replied
back there to me.