Working Trot - Sitting or posting?

Hehe as have I, little did you know.... ;)

I wsa just thinking about this. I watched a competition not so long ago.. L dressage out here, which I suppose would equate to 3rd level for you guys...

I knew a few of the competitors, and one rider was marked down for wrong diagonal when at a point in the test they were rising, not sitting.

Different countries, different rules?