Dropping trailer?

One of our trailers has this instruction plate attached by the leg handle. I’ve never been told to do this, what is the reason for doing this, does anyone actually do it?!

Cheers

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I can only imagine its something to do with the levelling system. If a loaded trailer is emptied the air bags will lift up the back having a cantilever effect on the front. This in theory could tilt it down enough that the next driver might not get a unit under it without winding it up in low gear first.
It could be something totally different though?

Its to help increase the life of the airbags on the trailer and to help relive them of the stresses of loads/forklifts banging in and out of the back of the trailer.

Some companies now have it that when you disconnect the red air line all the air dumps from the airbags too so its a good job to wait for the air to release before winding down the legs.

Thanks for the replies, that makes it a lot clearer

Cheers, Nez