Today at ORD (T3/AA), the line for the Family / Medical Liquids Lane (Green Lane) was much shorter than both the regular line and the Priority AAccess line. As someone who travels with a medical liquid (178 mL-- an Rx with an Rx label on it, not that that part matters), I elected to use the Green Lane.
The contract employee refused to let me in-- even after I pointed to the sign, showed her my medical liquid and had her read the sign, she still said it was only for strollers and wheelchairs.
Then she agreed to ask the TSO on duty at the head of the Green Lane. At that point, I had already followed her and the TSO said that having a medical liquid in and of itself is not grounds to use the Green Lane-- you have to have some sort of disability or be a family with small children.

She said (three-striper, by the way), that since I was already there, I could use the line this time. When I ponted to the sign and its clarity, she still said I was wrong.
At least she took my NEXUS card without so much as a blink. ^
Here is the exact sign that was posted:
http://www.tsa.gov/blog/uploaded_ima...ure-714828.JPG
Is my understanding of the rule wrong? I thought the sign was pretty clear. I will complain to AA since it is their contract employee that guards the Lane.