Originally Posted by flysurfer
Don't worry. The powers that matter (aka check-in agent) know that you are "important" (aka SEN), anyway. Otherwise they wouldn't have let you use the F check-in in the first place.
Also, using a big
luggage tag in order to avoid carry-ons to become
luggage sounds like an idea right out of the TSA brainpool.

Check in agents may know that you are "important" but quite often the gate agents do not. AT LHR especially the red tags on hand luggage help to head off requests for it to be checked in.