French rules say you must have a transponder to enter class D. This makes visiting France a pain with no transponder. This rule is not well enforced, but if you get ramp checked.
LFAT: Squawk 1234
G-ABCD: Negative transponder.
LFAT: OK, follow the coast and call me abeam Boulogne
The next call elicits landing instructions, effectively granting authority to enter class D without a transponder. Would a ramp check not take account of that?