As informed by my friend (a hotelier), the 10% service charge is only imposed if you dine-in at the outlet. If you do take-away, you won't be charge the 10%. His reasoning is that, when you dine-in the staffs will have to serve you the food, entertain whenever you call to ask for chilli sauce/tomato sauce/pepper/tissue/whatnot. Whereas when you do take-away, they just prepare your food and off you go.

I don't know whether this is applicable for all outlets, I'm sure it should though, but whenever I did take-away at McD I didn't see them charging 10% on my receipt. Different if I dine-in, then they'd charge the 10%. Not sure about now whether they still practice this, long time never eat fast food already. Would be nice if somebody who dine-in and take-away can keep their receipts and clarify this.