Question: What is the difference between a flank and a slide in marching band?
Answer: Good question! They are both the same movement except for where your shoulders point. On a Left Flank you will pivot on your right foot to your left, your hips and shoulders will face to your left- an ‘agreement’ of hips and shoulders. On a Left Slide, you will execute the same movement with your foot and your hips facing to the left, but your shoulders will face front, a ‘disagreement’ of the hips and shoulders.
In this picture, courtesy of Vimeo, you can see the woodwind players at front sliding to their right (your left). There are also three brass players sliding as well in the top left of the photo. And yes, Drillers can slide too- it just takes imagination on how to use this technique appropriately.