That reminds me of many years ago when I drove high roof transit all the time. The club installed a gate system so the travellers could not get in. First time I had to drive to the gate stop get out check the height get back in edge forward get etc for several times to ensure I could get under it. What it said on the gate and what it said in my handbook made me be very cautious. At my age 2.2 metres does not convert well to feet and inches in my head.
Cue next traditional rank joke......
Army Captain addressing RAF Chief Technician. “If you were in the Army, Chief, you would be a Staff Sergeant “
Chief replies “If I was in the Army, I would be Major!”