What is that next to the battery marked M??

[supraman215]

It looks like some kind of placeholder for a slot for something, it doesn't open easily and I don't want to break anything so I didn't force it. It's right next to the battery under the back cover. Anyone know what it is?

 

[Andrew Martonik]

Just a marking from the production process. Don't think it actually means anything.

 

[supraman215]

it's a deliberate mark, it's part of the casting it's not a mark made during production.