What are the effects that remove guard and rest orders?

The base game book says only hero takes wounds, uses order or starts next turn.

I have seen refence sheets say also that moving, changing order and changing equipment also remove this. I know this is true of aim, but what about Guard and rest?

You can't place a new order if you currently have one, so "changing order" shouldn't be a removal criteria for anything.

Suffering wounds or using the order removes everything except dodge.

Starting a new turn removes everything except aim.

Moving or changing equipment only removes aim. Which is kind of odd, because aim is already easily the weakest order, but there you go.

Antistone said:

Of course you can change an order via someone with leadership.

I believe the manual covers all reasons those orders would disappear. If it doesn't mention a specific action, assume that action is fine.

Royaldoy said:

I am aware of nothing that implies this is possible. Leadership allows a hero to place an order when it's not their turn, but it doesn't say it lets you remove an existing order or have two at once, so the normal restriction should apply.

JitD rules page 14:

A hero can only have one order at any one time. A hero that has already been issued an order cannot receive another order until the first order is used or removed (see below).